Hi @LF0Kid welcome.
I have a little section in a video I made recently which you can find here. As well as depth and divisor mentioned by @ethancrawford, you should also look at envelopes as well. As I do a fair amount of FM synthesis both in Ableton and eurorack, envelopes and VCAs are particularly important. So I try to cover a bit of this in the video.
Hope that helps.
Cheers
Hussein
Hi Hussein! Amazing because om very interesting in making FM synthesis with Sonic pi and this video is helpful! Thank you
Hi @LF0Kid glad to hear it.
Let us know how you get on!
Just wanted to say hello. I’ve become quite infatuated with Live Coding recently. Programming and computing has always been fascinating but intimidating to me. I’m absolutely delighted to have found Sonic Pi, as it is “clicking” for me. Looking forward to learning with you and getting deeper into the space 
Hello, just joined… just found sonic PI, very curious to get it going and use it for my game dev
having trouble getting it going, it errors out on boot currently