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!