u/pasta-carbonara

hi guys! I want to renovate my bathroom and I'm about to contact some contractors for estimates and quotes. Basically, I want to change the floor (to porcelain tiles), change the vanity, the fixtures and the shower door.

I've never done this before and I don't know what to expect lol what are some things that I should be asking them? I'm pretty worried because it's my only bathroom and I really don't want this to last longer than it has to.

Any tips/advice? Thanks!:)