When you tap and open a person's profile, you can select "Battle" on their profile and it will pull up the prompt for you to attack them. Or, you can access the "Meet People" list by scrolling your phone to the left and pulling up the social tabs of the game. There should be 4 prompts that pull up in order for you to battle: Fight, Dance, Prank, and Eavesdrop. Eavesdrop allows for you to examine the other person's or opponent's dorm to see what type of mates they have in there. It would also give you a percentage for how well you should be able to hit the person. 80%+ is good to me for an average. Prank is used to "steal health" from your opponent's strength and intelligence bars. Both fight and dance use strength and intelligence respectively in order to take cash from your opponent.
Go to your wall and their should be an edit button on the top right. Select the post you want to delete and press delete (bottom of your screen). There has also been a issue where the edit button is there but it wouldn't work.. If you are experiencing that issue go to friends and go back to wall and edit. Here is a link to a Guide for New Players to get you started. I recommend you go to the Guide section of forums and read some other guides also! Like Guide to Jobs, EC, FAQs..etc. Maybe you just haven't bump into one on this game yet. but now you have. ? I'm Chinese