Hello David and welcome.
Firstly, we don't use the word can't, everybody can paint, it just takes a bit of patience and practice.
A basic figure is like a drawing, just stay within the lines. Ability to paint well is not judged here, we
Just want artists to enjoy painting, but flats are what we enjoy most.
As Mark said, there are many examples in the forum, if you become a full member of the BFFS you can get into the workbench areas where we post figures at various stages, it gives a good guide with various techniques and colours.
Art classes will give you the basics of form, shape and colour, a flat figure already has the first one,
it is learning the basics of colour that may really help and how to apply it. Shape is created by shadows and highlights, so creases and folds are painted. If you really want to get technical then cast shadows from one directional light source can be added.
Do you like the fine detail work, or the looser style of Monet? All these techniques can be adapted to a flat figure.
Most of all, paint to how you feel comfortable, and if you are pleased with the end result then that is all that matters.
To really enjoy your painting, and to really relax with it, chose a subject you want to do.
When you start, post pictures and ask questions, however silly you think they may sound, we are here to help.
As Chris Seeley says, welcome to a flat world