I need help!!! Whenever I try to pick up an item, watch tv, or sit on the sofa, it says You can't do that. HELP!!!!!!

Calm down. Is this in a game you're making? If so can you provide information on what you did when making the objects and such...

Sounds like you've put the objects into a room and started up your game.

I think I know what the problem is. On the objects, click the second tab 'inventory', make sure that under taken 'yes - automatic' is selected or you can't pick stuff up.