I can't upload codes to my ARDUINO NANO

I am new to this ARDUINO World...I have many doubts and cleared it by searches, but i can't find a solution for:HOW CAN I UPLOAD MY CODES TO ARDUINO BOARD USING PC.

I am using Arduino IDE 1.8.8, Arduino Nano and USB Mini-B cable...
First i made a 444 LED CUBE and i can't upload my codes to board but the thing is 'i uploaded the code using my mobile'...but is is hard for me to use mobile for all code uploading procedures like uploading a code then resetting the board etc...And i have to write the code in my PC and send it to my mobile through Whatsapp and upload it from mobile using Android version of ARDUINO IDE...
So, anyone please help.....

Really need to post the error .. but looks like this has occurred before and you need to select processor as 328 with old bootloader from the sub menu and retry.