Here's a tutorial! https://www.drivenbydecor.com/how-painting-bathrooms-ceramic-tile-floors-diy/
First you must sand then so the paint will stick, then paint.
Hi Awilda, Use porch and floor paint because it is more durable for floors. Use a primer first and most people clean their floor with TSP cleaner.
I updated my tile floors without paint, it was so much easier. You can see it here: https://thehoneycombhome.com/floor-stickers-in-the-bathroom/
I painted our entry way tile using chalk paint. See the tutorial here: https://www.aratariathome.com/blog/painted-tile-tutorial-entry-way-makeover-part-2