Can l lay vinyl tiles over ceramic tiles in my kitchen and bathroom

not without prep. Depending on the height difference between the grout and the tile, you'd either need to lay luon (thin plywood-type material) or may get away with a leveling compound for a very small area. The vinyl tiles need a flat level surface that a ceramic tile floor just isn't.

I have seen someone try it by buying the same size vinyl tiles as the ceramic and putting the vinyl perfectly over the top of each ceramic tile and then grouting between the vinyl tiles over the old grout. It looked pretty good, I'm not sure how long it lasted though.

NO! The ceramic tiles with grout are uneven and will transfer to the vinyl tiles. The vinyl tiles may not stick properly due to the uneven surface.

http://homeguides.sfgate.com/install-vinyl-tiles-over-ceramic-tiles-bathroom-39993.html

I would suggest a professional consultation with a flooring specialist before you follow anyone's advice .....