What to expect with working with mixing engineer?

I have always produced in the box and completed tracks on my own but never formally released any. With that said, my experience typically resides on the tracking and recording side, but ultimately a musician first and I'm really just focused on getting the music recorded/arranged etc

Anyways, is the scope of work from a mixing engineer narrow/strict in the way where they are only going to balance/glue the tracks/mix, where gente/style is irrelevant because they are strictly focused on the technical?

I am not looking to them for full-on producer work, but the stylistic side is sort of a grey area for me. Certain genres for example, tricks to bring elements out or into a certain style like reverby vocal of darkwave, ambient stuff, etc. Is it the job of the person recording the project to bake in these things, or at least record a wet track separately to be mixed? I guess my skillset is limited when it comes to managing the eventual mix as a whole to shape and glue that sound together, and not entirely sure how the different stages and relationships work together since I've always just sorta done it all myself for fun.

I want to give these tracks the proper treatment and know if I try to mix it myself, I'll be hating on it a year or two from now as I learn and grow lol. I want to handle it right and formally release it, but don't want to compromise/lose the sound and style in the process when trying to work/collaborate with a mixing engineer.

Any insight on the process and relationship would be greatly appreciated!