How to paint my tile floors?

A good epoxy paint will work, however you will still have to seal it to keep the floor from chipping.

It will be difficult to apply the paint adequately enough so that it is durable for a floor if the tiles are an uneven surface. Attempting this may result in a bigger problem in how to remove half-on and half-off portions of paint.

So many ideas. So many ways.

https://www.hometalk.com/search/posts?filter=paint%20tile

I agree with Flipturn, the uneven, textured surface will wear off quickly, but that shabby worn look could be kind of neat.

Here's a link to several Hometalkers who have done this. Look for one that interests you and then you have your instructions and you can ask the Hometalker any questions you might have - https://www.hometalk.com/search/posts?filter=paint%20tile

If you get a quality bonding adhesion primer and roll on a few coats then paint and seal, you should be fine. You can see how I used those materials here: https://www.flippingtheflip.com/2019/03/how-to-stencil-paint-ceramic-tile-floor.html?m=1

This is a wonderful tutorial showing you how to paint your tile floor: https://www.youtube.com/watch?v=4aYZ5cfUD5Q