I'm sure i'll sound like a douche, but bro, you need to figure out how to lift BEFORE you even start researching steroids.
You need to figure out diet, routine, what works for you, it takes a long time man, it takes years!
I mean I could bench 130x6 when I was 15 and I had been lifting for literally 3 months.
I was like you, on and off for a long time, but I buckled down, got FVCKING serious, and got my bench max to 325 before I touched anything anabolic.
That's just an example though, I don't want to pretend that everyone need to bench X and squat Y before they're ready because everyone is different. But it's an indication of how much work you've put into it.
Basically if you are still figuring out how to lift, your gains are impaired because there's a host of inefficiencies because there's weak spots all over in your routine and diet and lifestyle. That seriously impairs the steroids and makes it not worth it!
And genetics isn't a crutch like that man! My friend was like you, weak chest, asked his dad about it, dad said his family has always had a weak chest (but strong legs).
But after 1 year of natural lifting he got his bench max from 180 to 260. THis was back in the day...
Anyway I'm not trying to diss you but I think you should figure out weightlifting and learn how to GROW a lot more before you start this!