Think I am in trouble!!?

Hi my name is Jess and I am 11 twelve next week.I think I am in trouble and don't know what to do?? My parents have been going on about my attitude for about two weeks and I have been told not to leave the house until I change, but on sat they went out and my sister was looking after me, I ignored my sister and went to a party now she is saying she is going to tell mum and dad. Today mum was asked to go to school about me, I think it is because on the Friday before half term some friends of mine who I was with chalked all over the hall, I did not do it! I was just with them, but because I was laughing i am now also in trouble! I was grounded a couple of months ago for telling my mum to shut up- it was in the heat of the moment and I did say sorry. I am suppose to be going out with my friends for my birthday and now I don't think they will let me...... What should I do???