I think your next step is to learn about compatibilism (the notion that free will is compatible with determinism). Compatibilism is the main view held by materialist philosophers today.
Framing free will as determinism vs. randomness works only if you equate free will exactly with randomness. If free will has anything to do with agency, randomness is not free will.
Thanks for the feedback. I didn't include compatibilism because I don't think that's the kind of freedom people think of when they think of free will. If you are free to choose to live by your own rules, but the rules you live by are determined by your environment, how can we really call this free?
Cheers