My baby's 1st birthday is coming up & I don't know what to do ?

I have everything done except for the "entertainment".I know he is only 12 months but he is very attentive and likes looking at things and dancing.I'm having his party at the park because the expected turn out is more than I'd care to stuff in my home.So I was hoping I could get some party ideas for a 12 month old birthday party.Answers from experience only please!