If you want to dabble with spray painting, years ago I learned to "spray-paint" my models using a Badger 250 and ProPel (canned gas). It worked just fine (I was using Floquil at the time), and it's still an inexpensive way to get started (I've seen a complete kit on Amazon for around $30).
Sokramiketes' advice is spot-on for brush painting Modelflex or other water-base acrylics. I've used Modelflex this way from time to time. My problem is the "walk-away" part - I always try and over-work the paint. Don't!
George