I have not any prior experience with installing custom ROMs, but after trying it out (and getting stuck, and googling and finding answers) I successfully did it. Below is my home screen if anybody is curious:
I use OpenBoard for my keyboard. Unfortunately I am still dependent on Play Store since some of the apps I need can only be found there. Sometimes it feels meaningless committing to this whole thing because I'm not perfectly private; then I think this is better than using a regular iPhone or Android phone.
So far I'm liking it. I am naturally inclined to feel hesitant about using this as my main phone and plugging in a SIM since it's custom, but I'm slowly making the transition.
Feel free to share any beginners advice or your own experience using GOS for the first time. Cheers!
Check out Heliboard (also on F-Droid) and follow the instructions to enable gesture typing. I also suggest Futo for on-device voice to text.
What specific apps are you using that you can't deal going away from? Other than some social media or gamr or something. Even then it seems like there are replacements a lot of the time