BMP280 code not compiling for Arduino Nano (Atmega328)

So I'm basically completely new to Arduino (I've had some exposure before, so I understand the very basics of it), but right now I am trying to load code for the Adafruit BMP280 (barometric pressure/temperature sensor) onto an Arduino Nano for a science project. I did not write the code myself but I instead got it off of Github. The issue is that when I try to compile it, the programmer says "Error compiling for Arduino Nano board."

I copied the actual verbose error message, which reads:
Arduino: 1.8.2 (Windows 8.1), Board: "Arduino Nano, ATmega328"

C:\Program Files (x86)\Arduino\arduino-builder -dump-prefs -logger=machine -hardware C:\Program Files (x86)\Arduino\hardware -tools C:\Program Files (x86)\Arduino\tools-builder -tools C:\Program Files (x86)\Arduino\hardware\tools\avr -built-in-libraries C:\Program Files (x86)\Arduino\libraries -libraries C:\Users\bigsu_000\Documents\Arduino\libraries -fqbn=arduino:avr:nano:cpu=atmega328 -ide-version=10802 -build-path C:\Users\BIGSU_~1\AppData\Local\Temp\arduino_build_189173 -warnings=none -build-cache C:\Users\BIGSU_~1\AppData\Local\Temp\arduino_cache_314593 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avrdude.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avr-gcc.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -verbose C:\Users\BIGSU_~1\AppData\Local\Temp\arduino_modified_sketch_713773\bmp280test.ino
C:\Program Files (x86)\Arduino\arduino-builder -compile -logger=machine -hardware C:\Program Files (x86)\Arduino\hardware -tools C:\Program Files (x86)\Arduino\tools-builder -tools C:\Program Files (x86)\Arduino\hardware\tools\avr -built-in-libraries C:\Program Files (x86)\Arduino\libraries -libraries C:\Users\bigsu_000\Documents\Arduino\libraries -fqbn=arduino:avr:nano:cpu=atmega328 -ide-version=10802 -build-path C:\Users\BIGSU_~1\AppData\Local\Temp\arduino_build_189173 -warnings=none -build-cache C:\Users\BIGSU_~1\AppData\Local\Temp\arduino_cache_314593 -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.arduinoOTA.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avrdude.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -prefs=runtime.tools.avr-gcc.path=C:\Program Files (x86)\Arduino\hardware\tools\avr -verbose C:\Users\BIGSU_~1\AppData\Local\Temp\arduino_modified_sketch_713773\bmp280test.ino
Using board 'nano' from platform in folder: C:\Program Files (x86)\Arduino\hardware\arduino\avr
Using core 'arduino' from platform in folder: C:\Program Files (x86)\Arduino\hardware\arduino\avr
Detecting libraries used...
"C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10802 -DARDUINO_AVR_NANO -DARDUINO_ARCH_AVR "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\eightanaloginputs" "C:\Users\BIGSU_~1\AppData\Local\Temp\arduino_build_189173\sketch\bmp280test.ino.cpp" -o "nul"
"C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10802 -DARDUINO_AVR_NANO -DARDUINO_ARCH_AVR "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\eightanaloginputs" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\libraries\Wire\src" "C:\Users\BIGSU_~1\AppData\Local\Temp\arduino_build_189173\sketch\bmp280test.ino.cpp" -o "nul"
"C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10802 -DARDUINO_AVR_NANO -DARDUINO_ARCH_AVR "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\eightanaloginputs" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\libraries\Wire\src" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\libraries\SPI\src" "C:\Users\BIGSU_~1\AppData\Local\Temp\arduino_build_189173\sketch\bmp280test.ino.cpp" -o "nul"
"C:\Program Files (x86)\Arduino\hardware\tools\avr/bin/avr-g++" -c -g -Os -w -std=gnu++11 -fpermissive -fno-exceptions -ffunction-sections -fdata-sections -fno-threadsafe-statics -flto -w -x c++ -E -CC -mmcu=atmega328p -DF_CPU=16000000L -DARDUINO=10802 -DARDUINO_AVR_NANO -DARDUINO_ARCH_AVR "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\eightanaloginputs" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\libraries\Wire\src" "-IC:\Program Files (x86)\Arduino\hardware\arduino\avr\libraries\SPI\src" "C:\Users\BIGSU_~1\AppData\Local\Temp\arduino_build_189173\sketch\bmp280test.ino.cpp" -o "C:\Users\BIGSU_~1\AppData\Local\Temp\arduino_build_189173\preproc\ctags_target_for_gcc_minus_e.cpp"
C:\Users\BIGSU_~1\AppData\Local\Temp\arduino_modified_sketch_713773\bmp280test.ino:20:29: fatal error: Adafruit_Sensor.h: No such file or directory

#include <Adafruit_Sensor.h>

^

compilation terminated.

Using library Wire at version 1.0 in folder: C:\Program Files (x86)\Arduino\hardware\arduino\avr\libraries\Wire
Using library SPI at version 1.0 in folder: C:\Program Files (x86)\Arduino\hardware\arduino\avr\libraries\SPI
exit status 1
Error compiling for board Arduino Nano.

The code itself reads:
/***************************************************************************
This is a library for the BMP280 humidity, temperature & pressure sensor

Designed specifically to work with the Adafruit BMEP280 Breakout
----> Adafruit BMP280 I2C or SPI Barometric Pressure & Altitude Sensor [STEMMA QT] : ID 2651 : $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits

These sensors use I2C or SPI to communicate, 2 or 4 pins are required
to interface.

Adafruit invests time and resources providing this open source code,
please support Adafruit andopen-source hardware by purchasing products
from Adafruit!

Written by Limor Fried & Kevin Townsend for Adafruit Industries.
BSD license, all text above must be included in any redistribution
***************************************************************************/

#include <Wire.h>
#include <SPI.h>
#include <Adafruit_Sensor.h>
#include <Adafruit_BMP280.h>

#define BMP_SCK 13
#define BMP_MISO 12
#define BMP_MOSI 11
#define BMP_CS 10

Adafruit_BMP280 bmp; // I2C
//Adafruit_BMP280 bmp(BMP_CS); // hardware SPI
//Adafruit_BMP280 bmp(BMP_CS, BMP_MOSI, BMP_MISO, BMP_SCK);

void setup() {
Serial.begin(9600);
Serial.println(F("BMP280 test"));

if (!bmp.begin()) {
Serial.println(F("Could not find a valid BMP280 sensor, check wiring!"));
while (1);
}
}

void loop() {
Serial.print(F("Temperature = "));
Serial.print(bmp.readTemperature());
Serial.println(" *C");

Serial.print(F("Pressure = "));
Serial.print(bmp.readPressure());
Serial.println(" Pa");

Serial.print(F("Approx altitude = "));
Serial.print(bmp.readAltitude(1013.25)); // this should be adjusted to your local forcase
Serial.println(" m");

Serial.println();
delay(2000);
}

Now, I'm not quite sure what the problem is, but from what I was reading, it may be related to I2C vs SPI. I'm not real sure on the major differences between the two, other than the fact that when I switch them I need to change the pinout. After doing some research, I still wasn't able to tell which values I should change. Can anyone help me figure this out please?

(deleted)

I most certainly did. Thanks!