Thanks for solving my questions. Iv'e been struggling on these for days! I hope this can help other people too!

OK, thanks! Also, I'm wondering if when I run code if it will automatically run on the Raspberry Pi. Like if I make code to use a temperature sensor would it use the temperature plugin automatically even if I unplugged the HDMI from the display?

I tried looking at many different websites and tutorials and I still don't know where I need to put the Python code to run it. Is there a special upload process? Do I need to put the program on the Micro SD card? I have Raspberry Pi 3 Model B. (I don't know if it is B or B+)