It looks like tile but pretty hard to tell from the pictures. What is the green thing in the tub area? The walls IMO definately need to be painted a neutral that works with the floors and the counter for now.

okay. The green thing was left by the previous owners. It was to hold kids tub toys. it's a frog.

Sure looks like tile, and you don't want to go there for your first DIY project. Start with painting. Read a lot about painting before you start, you want to prep the walls properly. How high is the ceiling, do you feel safe painting it?

Also easy to replace cabinet hardware, towel racks. Fairly easy to replace light fixture.