Is it a factory finish or has it already been homeowner painted? Prep is 90% of any paint job so they will need to be sanded/ deglossed and super cleaned.

Start by watching some YouTube videos on the process. It is basically this: Deep clean/de-grease (even if they look clean, they are not), sand, (sand finer, i.e. 220 grit), prime, sand a little if you need to remove an imperfection, paint on (or spray on) the proper coating sanding between coats.

The right coating is not actually paint, but a urethane enamel like Sherwin Williams Emerald Trim Enamel - there are other options, but S&W is highly rated. The technique below is far from perfect, but it’s a good place to start. Move up in technique complexity as your own OCD requires. We’ve had houzzers who built their own spray rooms. Good luck!

Clean them well, even if you think they are clean. Sand them well. Make sure you have a dust free enviorment. Prime them, with a good sealing bonding primer. Paint them, with a good quality paint, that is meant for cabinets, not regular type paint. No shortcuts when you are painting cabinets. Prep is a lot, and it takes a while to get them all painted correctly. Anything less, and you will end up with chips, and peeling, and a lot more work, fixing all the errors.

Painting cabinets successfully to not look like somone accidentally just spilled paint with drips and runs and gaps, is a lot of work. The Kitchen Cabinet Painting Experts group on Facebook has the step by step instructions as to how to do that. If the paint is a poor job, or not adhering, replacement of the doors is better than stripping those like they need.