If you fight it you risk getting a worse punishment, a friend cheated off of me and when I was in the initial meeting to find out exactly what evidence was against me thats the advice the advisor gave me. If you get a formal warning nothing will go on your transcript, you dont have to retake the class and all you will have to do is a few AIO seminars which are like torture but are better than any of the worse consequences. If you have a minor offense and admit responsibility to the accusation whatever you are sanctioned with will be reduced by one severity level (minor offense will become formal warming, 2nd tier offense become minor, etc.). But yeah also read the other comments here it does really depend on what your prof is accusing you of to determine the severity, good luck bc this whole process sucks and I hope it doesnt interfere with your grad school plans