This is a boon for people new to RL, congrats! After looking at the implementations, I am curious whether you have heard of SaLinA? It's a lightweight library for RL (and sequential learning in general), with a design philosophy that's very similar to CleanRL.

You can also have a look at these later surveys that give an idea of the different types of GNNs. Also if you prefer Tensorflow you can use the Graph Nets library.