Also, OP, dont be afraid to jump straight into mods. You dont have to fuss with a single file. Right from the start, inside the client, you can join modded multiplayer servers. The mods are automatically installed and applied then and there. Zero setup! I say this because a whole heap of mods are strictly quality of life and they really ease the learning curve.
However, picking and choosing your own mods for your own server is the headache you might expect. Let some saintly admin do all that work for you.