Help me understand difficulty of ownership

I’m looking to buy either a Dart or a Duster in the $20k-$25k range.

My technical abilities are quite low - I have only done fluid and filter changes on my daily driver so far. But, I do have a garage at home and I am taking a night class at a tech school on how to fix cars.

I completely understand that something like a Mustang or a Nova would be easier for a beginner like myself, but I love these mopars.

How is owning an A Body in terms of part availability and repair work? Is it something that is feasible for a beginner like myself?