I am in the process of painting the inside of my 2004 BT Cruiser, as well as other modifications.
I spent many hours removing and sanding the cabinet doors. I am now sanding the cupboards.
When I finished, I checked into TSP and saw somewhere that if you do not remove all the TSP, the paint will not stick. I decided to go with an equal part water and vinegar to clean. Not too fond of chemicals anyway.
Next will be priming. The one thing that seems to be consistent in all the advice I have seen is to use an OIL BASED primer. That is what we will use.
Then paint with a quality latex paint.
There are many u-tube videos on painting. I have watched all of them before I even started to do anything. Good advice if you can filter out what you want and what you don't want.