-Try modpacks first before installing Modloaders like Forge, Rift, Fabric/Datapacks. I say this so it's easier for users to get a feel for mods before using Installers which most users use to create their own custom modpacks or use for other instances (Forge for most versions of the game to be modded, Rift for 1.13/1.13.2, Fabric for 1.14), using multiple different Modloaders can get confusing sometimes and isn't best to recommend to a newcomer, not so much the install instructions just going about all this stuff I think could be confusing if you aren't familiar with this sort of thing.
Using modpacks I think gives you an idea of not only what exists for mod possibilities but how people balance their games with mods also I guess.
Otherwise for finding modpacks here is a video on the types that exist out there:
Obviously once I know what things your into for Minecraft I can easily select mods that will suit rather than just a bunch of mods everyone says they use and it might not really make sense at all to a newcomer with such mod content or the mods and their elements might not appeal to you. Like if your not into Tech mods I won't suggest any but if you into Adventure, World Gen (Plants, Ores, Food, etc) then I'd recommend those besides the usual useful ones like JEI as a Recipe viewer/cheating option, or a Minimap to put on screen instead of Minecraft's fairly interesting map system that I've just gotten around to learning now.