...of adhesives can I use? And should use? Thanks.

two part glue, or silicon.

I use thin set mortar.

use a good floor glue (ARMSTRONG) that is designed for wet areas Once you have set your tile let the glue cure about 24 hrs then come behind yourself with the grout Let the grout cure for about 12 hrs and coat over with a good sealer due to the fact grout is porous When groying keep a sponge handy to keep excess grout off tiles and rent a ceramic tile cutter