Any used DSLR or large sensor mirrorless camera would be fine for any general photography introduction. Specifically, if you want to learn to use ISO and aperture values a larger sensor is important, as aperture has little effect in smaller sensor devices ( phones, tablets, most point and shoot cameras ), but is much more significant with large sensor devices.

Do not get distracted by megapixel counts. It's not so long ago that a 6Mp image from a DSLR taken by a pro would have been happily used in a full page magazine spread. I still have large prints on my walls that came from a 6Mp DSLR and kit lens ( mine, of course ).

Starting out a basic kit lens ( like an 18-55 ) is fine. They're actually pretty good lenses optically nowadays, and well suited to introductory landscape shooting.

The temptation to buy accessories and more lenses is normal. Resist it, as you'll most likely be wasting money until you have a solid understanding of your basic kit. Resist the temptation to blame the equipment for your problems in your photos - look for problems in your technique instead. Experience has taught me that it's usually my technique that messes up a shot and not my equipment.