A control surface is an unnecessary convienience. It's normally something you work up to, not something you start out with.
The difference between a mixer and a control surface is a mixer actually passes audio, a control surface just controls the computer (like a glorified mouse)
All is now cool this end. I think your initial question has been answered? Good idea to list what you have at the moment in terms of computer and its specc', instruments and genre interests.
OP, generally speaking, to get a control surface to work correctly in whatever daw, you need some kind of key map file(s) for that control surface and daw to 'map' faders/knobs/switches to specific functions. Like the first fader slide on the controller to track 1 mixer volume, the first knob to track 1 pan, etc.
Many generic control surfaces will contain key maps for the major daws, or be able to use a generic or universal key map (sometimes called something like a scene) to use in general then maybe an extra key map for specific groupings like mixer controls, tracking controls, something like that.
I have a Korg NanoKontrol2 I use for Reaper, and set the general control to the Mackie Universal MIDI in/out, then add a couple of Korg/Reaper specific key maps and it works great.
...but there are a few things even my little rinky-dink control surface can do that I love. I can set a fader to control groups of faders all set at different levels, and each fader on the control surface has different mode switches to multiply the functions.