Is the tile on your walls? I can't tell for sure, because you ask for wainscoating. If Wainscoating is what you want, its not that hard to do. You can create wainscoating with paneling, capped with a piece of trim moulding like a chair rail, then paint it. Pretty easy, and more likely to be something you can be proud of than risking trying to paint a surface not intended for paint.
If you insist on painting your tile, the first thing I would do is strip the surface with either an acid etch or a fine grit sand paper to "roughen up" the surface. You will need to prime the surface with something like BINZ, then a semigloss paint. Purchase your materials from a real paint store, like Sherwin Williams, (not a big-box store like **** Depot)and get advice from the paint people first hand when you do this. Paying a couple of extra dollars for a gallon of quality paint is worth it, because cheap paint is way more expensive if you have to do the whole thing over, or apply an extra coat.
Look at doing the wainscoating if that's what you really want, and read the postings over the last two weeks regarding crown moulding and chair rails. (hit ctrl-f and search crown or chair)