[2023] Questions from a relatively new ARPG player.

Hi everyone, I purchased last epoch a couple months back and took a break for awhile and now I am coming back. I am relatively new to arpgs (only playing grim dawn) and I have some questions for this game because based on the current titles, this seems like a happy medium to start at.

1. Is is it recommended to create a build or follow one online? When I played grim dawn I tried my own build but then eventually swapped to do more damage. I am not relatively good at building

2. What is the endgame like? I hear people say its "roguelike dungeons" some people say its like maps but I have no idea what those mean in the context of ARPgs

I thought LE was a good place to start because I like the skill tree diversity but I dont play the genre alot and was wondering if I could have someone explain it to me. Any help is appreciated.