If it's only one day before the tournament then you probably just need to relax. You really cannot try to improve your play in such a short amount of time. If you want to study, study basic tactics or other basic materials, but don't get tired.
Just try to have fun and learn. Don't focus on the results of the games. Playing against rated players OTB for the first time can be intimidating, but just try to relax. I actually prefer being able to see my opponent when playing.
I assume you know all the basic tournament rules. If you don't, ask the TD before the tournament begins.
guys I have one day left to attend my first fide rated tournament I am exited and little bit scared about OTB Against a real rated players please give me tips face this and suggestions which help me improve my play.....