I'm personally using UE5, as I'm not a coder so those blue prints and good UI (in comparison to Unity) is great for me =3

My friend, who is a 2D and 3D artist, used both Unity and Unreal, and he hates Unity so much and loves Unreal, mentioning that Unreal makes the life of a gamedev artist so much better in comparison.

Aside from that, another friend much prefers to use Godot than Unity. He's a coder.

To your question:

If you have a vision for a game, start immediately with figuring out how to make it's main gameplay loop, then develop it and see if it's fun to play. If yes, then move on to art, more features, music, etc.

Generally speaking, see I'd you can join a team in a gamejam event (an event to make a game within 48hrs based on a theme). Best way to learn and learn fast imo.