The unicorne is what I was thinking of, fully assembled in terms of the PCB (other than switches) which is less common for these boards. I've personally started to like low profile switches a lot, the reduced travel works really well for ergonomic layouts reducing finger movement. I will say they are not as refined as some of the recent mx style switches in terms of feel and sound, but ones like the sunset tactile switches are very good. Keycaps being the other limiting factor, chocs use different keycaps and there are not a lot of excellent options at the moment, but there are enough decent options that they're usable.

This is all good advice but I would say if you're willing (and interested) to try a "40s" like board, the corne (at least in 6 column version) is fairly accessible and is very popular so looking for ideas about how to make your keymap won't be difficult. And also boardsource now has a fully assembled version of the corne (no soldering).

That is to say, cerement described a very reasonable progression, but if you don't mind feeling like you don't know how to type for a bit you can jump into anything that is interesting to you, and many folks agree that smaller boards are more comfortable to type on.