sending data from sensor over wifi to separate arduino

hi, I'm a new arduino user and am beginning a project and would appreciate some guidance.

the objective is to connect a BMP180 (pressure and temperature) sensor to an arduino uno r3 and send the data via wifi (esp8266 module) to another arduino where the data will be saved to an SD card.

I'm a little stuck on how to go about doing this. first, i'm unsure what the best way is to collect the data from the sensor. does it first need to be saved to the arduino's memory and then sent from the arduino to the wifi module by giving the module the address of the data?

I've never worked with wifi modules before either. I've found a few examples online on how to send data from a module to, say, a website, but none on how to send from one wifi module to another.

any sort of help would be greatly appreciated. hopefully ive made my goal clear but if i havent please let me know.

Parts list:
2 arduino uno rev3
2 ESP8266 wfi module
1 SD card Reader
1 BMP180 sensor

Drop the Unos & WiFi modules, get a pair of ESP8266 boards such as the NodeMCU or WeMOS instead. It's got the WiFi built in, got more memory and speed, and works at 3.3V which means you don't need level shifters for your BMP180 (which may or may not be included in your breakout board of this sensor).

After that connect the modules to your home WiFi router, or make one a WiFi host and have the other connect to it. Set up a webserver on the master, the other sets up a web client and they can communicate simply over http by sending GET or POST requests.

Assuming you don't take readings crazy frequent the sensor module can just take a reading, send it out with an http request, and go back to sleep until it's time for the next reading.