What's a website that has free video game music for the games you make?
http://www.freesound.org/
Is that where you go? Or do you make your own?
It depends. There are enough tools to make your own music nowadays (I can recommend SunVox, which is quite powerful and the PC version is free), or you can search for music with Creative Commons license (like freesound.org, mentioned above).
Develop games in your browser. Powerful, performant & highly capable.
I don't typically use free sounds. I usually purchase them from Pond5.com
looperman.com for music loops
freesound for certain sound effects
danosongs.com & incompetech.com are two of my faves. (req credit)