Which version of Gregtech do you recommend? Haven't played in so long I can't remember much, I hear Nomifactory is a good place to start though. Also I hate how when I look for Gregtech by itself it's just GTNH, I get that it's far more popular due to the "this modpack takes x hours to complete" videos but damn...
Usually I'm not into turbo-tism mods like GT but fuck it, might as well know how to do it. AE2 is dope though, even if I only interact with a small amount of it. Been apart of my earlier modpacks all the way back in 17.10.
I definitely recommend picking one based on a modpack you actually have interest in playing. I haven't played Nomifactory but I have played Monifactory. If you've used AE2 to automate a mod like Thermal or Mekanism then you can definitely figure out Gregtech, it's not that hard. Being more complicated than the average tech mod is balanced out by offloading the bulk of the crafting/logistics to AE2. You should figure out how subnets work if you don't know, but channels are disabled by default in both of those packs. P2P is also good to know, but the rest is fairly straightforward. You should internalize using interfaces and GT covers for automation as opposed to import/export buses with crafting cards.
Side note: AE2 in 1.12 uses Interfaces for autocrafting and stocking, newer versions split up the functionality into Interfaces and Pattern Providers. It's not that complicated and AE2 has great in game documentation now, like Create's Ponder mechanic.
If you like Factorio and want to unlock AE2 as quickly as possible, then both Nomi and Moni are solid choices. Nomifactory is finished and everyone says that makes it more satisfying which I have no reason to doubt. It's on 1.12 and may be more familiar to you if you're used to playing 1.7 Minecraft. Also the Monifactory devs are planning to release a final update soon, so it might be best to wait until that happens.
Some other common suggestions are Star Technology for a skyblock, TerraFirmaGreg for an autistically overhauled survival/stone age, FTB Interactions for a bunch of integrated mods like Thermal and Blood Magic, and GTNH for the memes.
Now despite that, GTNH is anything but a meme pack. It is ridiculously polished because it has been developed for over a decade now. The quest book is second to none and the pack has a lot of custom features like multiblocks developed exclusively for it. Look for videos by Lashmak or Threefold if you want to learn more about it. The only caveat is that you are not really supposed to be able to beat it in any reasonable timeframe. It's 100% about the journey, not the destination. I would not recommend it for someone who hasn't played GT, but if you complete something like Nomifactory, then you might be interested in GTNH.
SuperSymmetry is worth keeping in mind, one of the developers is a physics scientist who works for CERN. It's nowhere near close to finished though. Gregtech Community Pack by Tech22 is apparently a good introduction as well. If you aren't used to playing expert packs then you may want to check that out.
I started playing GT in 1.20 so I'm spoiled by the
modern textures. You can install them on older versions too.