Want small snake, recommendations ?(beginner)

I've had a leopard gecko for 3.5 years now and I was thinking about getting a snake (when I get an apartment, because I still live with my mom and my room is tiny) but I don't want a big expensive and complicated snake yet. But when I look up on YouTube I can't find any informations about anything, or the ones I find are 800$+ which I can't afford yet. Does anyone have recommendations? Also with websites where I can get informations from ? Im scared I will do the same mistake as when I got my gecko, I got him from a breeder con type of thing, and he told me to put him in coco fiber and in a small tank (which was way too small, but he was a professional so I trusted him), then I went back and he told me to put him on sand ! Worst idea ever, and now he has a good big tank with red dried clay as substrate, but yea I don't wanna mess up with my next baby, so I don't trust "professionals" at cons anymore. So thank you if you have any links or websites or informations or recommendations for snakes ! :)