Installing a vinyl floor over a ceramic one isn't something you'd normally do, as most people would consider vinyl to be a step down from ceramic. There are exceptions, though. If the ceramic floor is old, worn and out of date, enough that you feel you can cover it permanently without guilt, then it actually will make a good underlayment for vinyl tiles, as long as it's flat, solid and clean. Let the vinyl tile acclimate to the environment for a week before installation.
Mix 1 cup (120g) trisodium phosphate in a bucket of hot water. Mop the ceramic floor with it. Rinse. Let it dry thoroughly.
Lay two perpendicular lines across the floor with your chalk snap line, intersecting in the middle, to divide the floor into four even quadrants. If the lines line up with the grout lines of the existing ceramic floor, then move your lines so they don't line up.
Spread tile adhesive over the middle of the floor, covering 4 to 6 square feet (1.2 to 1.8 square metres) encompassing the intersection of your lines. You will be able to see the lines through the mortar.
Set the first vinyl tile at the intersection, bordered on two sides by lines. Press it firmly in.
Set the second tile in place alongside the first, butting the edges of the tiles tight to each other.
Repeat, building the tiles off each other and out from the middle. Spread more adhesive as needed. Build out in a grid pattern along the lines. Lay all the full tiles that will fit.
Let the full tiles set overnight. Measure and cut additional tiles to go around the edges of the floor where full tiles didn't fit using a vinyl tile cutter. Let them set overnight.