It's a pretty complicated and difficult mod (both in regular playing and config) so I'd mostly recommend to just use a modpack tbh

imo the main packs to consider are

• the Community Pack
• Nomifactory - CE version - CEu version
• Gregtech New Horizons

Community pack is just a focused tutorial on Gregtech basically, I've heard it's good but I haven't played it personally cause I just immediately started with another pack.

Nomifactory is one of my favourite and most played packs. It has a lot of normal Gregtech grind and annoyances removed which is often nice IMO. There's 2 different versions (there's also Monifactory but I haven't tried it and it's in alpha, so I would avoid it for a first gt pack). The CE version is the main version (if you use this make sure to grab the 1.3 version under beta, not the 1.2 released version), and as such it's generally more polished (IMO just play this pack). The CEu version is on a different fork of Gregtech, it's more grindy in the early-midgame, but it's got a bunch of quality of life features in the late game, and it overall has somewhat more content IIRC. CEu also has a hard mode that I'm playing rn and it's a lot of fun but def wouldn't recommend starting with it. What I did was I first played NF CE version, and then the NF CEu hard mode. (Also as a note for length, IIRC NF CE took me ~500 hours to finish, so it's def a time investment but totally finishable)

GTNH is like the quintessential GT modpack. I still haven't really played it, but it's probably most well known for being insanely long. It's difficult, but has a good questbook so it's still approachable to newer players. It's not really intended to be a pack you finish, it doesn't really have a strictly defined ending and the point players usually use as an ending (crafting a pair of stargates) gets made harder occasionally (I think there's only been like a few hundred people who got to that point anyways?). It has good progression tho so the main way ppl play it is just as a pack that you can kinda just play and enjoy forever.