Golanlan

I'm new to STEP, and wanted to ask if I go with the STEP:Core patch, then I go and install all the "core" mods, but then I see some mod I know I dislike, then is it possible for me to skip it? What about when I go through the "core" mods, and then I see a mod I really love, but it's at the Extended categorie.. Is it OK to install it? How strict is this system?

How do I start with it? I have no idea what i'm missing, I've tried googling for help and scanning the front page..