Making My Backyard Look Pretty For My Party!!

Ok for my friend and mines Birthday on Friday we`re gonna have a boy-girl party at a hotel. And the girls are gonna stay the night. Thats mainly my friends b-day party. Then on Saturday I want to have a BBQ at my house (just with some girls and my immediate family). I think that I have a good enough sized yard BUT my yard has alot of cars and a dog thingy so it takes up most the space. Give me some ideas on how to make my yard look pretty for the BBQ. I think that later we might go to the Mall and maybe a movie (not sure about the movie). I could also use some other ideas on wat to do. ANYWAYZ back to the yard- wat should i do to make it look pretty. Oh then with my immediate family coming there will be 3 other cars in the yard! HELP