Use a good primer and just go for it! Where is your ceramic tile at in your home?
For it to hold up, use the epoxy kits,made for that sold at home depot. Step by step instructions are in the kit. Prep is very important. Realize paint on ceramic tile in high traffic areas will require some upkeep. If in wet areas like a shower, once scratched will peel. Usually last long enough to save up for a remodel.
Hi Carolyn, here's a DIYer who tackled a backsplash. https://www.hometalk.com/20022455/-don-t-paint-ceramic-tile-they-said-
And one who did a floor. Not sure what surface you're planning to cover. https://www.hometalk.com/31754162/how-to-paint-a-floor-with-a-tile-stencil
Hope that helps!
Check local Home Depot. Ask at paint counter. They make special paint for it.
Here is a solution other than painting it: https://thehoneycombhome.com/floor-stickers-in-the-bathroom/