This isn't exactly an RPG... And, no, this game is also not only about slaying bosses, either...

This game is mostly about surviving in a harsh wilderness. Gathering, crafting, farming, raising lifestock, building, mining. That's the main game loop. It's a survival sandbox.

You can actually play the game without ever laying hand on a boss. Or using portals. Or both. Or maybe you want to make it harder and turn off the map?

There are many ways to play this game, but it is not:
a. an RPG.
b. a pure action title.

As for the topic: There are many mods available through the "ThunderStore" mod-manager, which I would highly recommend installing if you want to dabble with mods. It helps you to keep your mods up-to-date. There's a huge online download repository with over 1500 mods to choose and download from, all through the manager. ThunderStore can also resolve dependencies, and you can individually en- or disable mods, or disable them all together for a plain vanilla experience in case something goes totally wrong.

Mind, IronGate currently does not support mods, and you're on your own when you encounter an issue with them. Just a friendly reminder.