If you want to learn about camera controls AND get great photos you could do a lot worse than buying a used Canon 1200D from Ebay.
You can usually get a bag of camera + a couple of lenses for <£200
I use a Canon EOS 100D. You can pick those up for <£200 used now. I rate it very highly.
Then, in a year, you can Ebay it all for about the same money when your DLSR experience has taught you whether you want a better DLSR or another form.
It will probably cost you about £30 in depreciation and the results will be staggeringly good compared to a phone.
By that time, if you want mirrorless, there will most likely be a new generation of them on the market (allowing you to pick up the current generation cheaper).
The big advantage of a Canon DLSR is the range of lenses, new and used, that you can stick on the front without an adapter.
You can pick up a used 50mm "portrait lens" for £50 that, used correctly, will amaze you (if you are used to selfies taken with a phone).
I'd be surprised if you bought a used kit that didn't include the 50mm f/1.8.
It's really got to the point where, image-qualitywise, you need to start "pixel-peeping" to spot the difference between the cameras from the big manufacturers.
A 10x8 print won't reveal much difference, if any.
Point the "Plastic Fantastic" Canon 50mm at someone's face, set it to f/1.8 and start shooting. You won't be disappointed.
Edit. I'm certainly not making any claims for this photograph apart from it's one of the first shots I took after I bought the 50mm f/1.8, and it shows the effect I want.
It's that shallow depth of field (blurred background), to isolate the subject, that most people associate with DSLRs. It's not unique to DLSRs (even Phones can "spoof" it with software now) but a Canon off Ebay + a 50mm f/1.8 is a cheap way into it.