I don't know why you would assume, despite the fact that it's used in so many film pipelines, that it's a piece of crap
Honestly, if you are a newbie, the differences between renderers won't matter very much like someone else said. The main reason I use renderman is because I like shading/lookdev in it.
Anyway, as someone who primarily uses renderman, I can say it's very easy to set up and get a high quality render, it's not as complicated as the REYES days. however, as a brute force gi CPU renderer (like arnold), the tradeoff in ease of use / simplified controls comes with longer render times generally. it can be a bit hard to optimize. If you want more exposed flexibility plus more online resources, I would suggest Vray instead.
If speed is very important to you, check out Redshift, it's been pretty hype although I haven't used it myself.