To see if you like the process but don't want to spend a ton of money:

• $5-8: Dollar acrylic paints at a craft store. Get primary colors, black, and white
• $2-5: Any brush set that has at least a pointy brush and a fuzzy looking brush
• $5-10: Either a single mini like a DnD character mini, or to see if you like army painting get a bag of green army men

And you're good to go! Thin the acrylics with water, abuse your cheap brushes, learn dry brushing, and attempt to make and use a wash (basically just very thin paint sometimes with a tiny amount of soap). If you want to get fancy with bases grab some dirt, rocks, and twigs from outside then stick them on with thinned down white craft glue.