What can I expect behind the tiles?

My bathroom in my new house has the ugliest green tile halfway up the wall and then a different shade of green tile on the floor. My husband & I have a little experierience with fixing stuff up, but this one has us puzzled. We want to tear the tile down and put up drywall. Then we'd like to carpet the floor. We haven't got the nerve yet cause we don't know what to expect behind those tiles on the wall. Got ANY suggestions in my little dilemma???