Party Planning

My son's 3rd bday is next month (10/25) and I am trying to get some ideas together to figure out all the details for his party. I think we are going to have a more simple party this year- at a park. Clayton would be outside 24/7 if we would let him, so I think he will like having his party at the park!! He is really into Mickey Mouse Clubhouse and tractors of course (John Deere to be exact) and I asked him, "Do you want a Mickey or a tractor party?"...although I dont completely think he understands that I am referring to the "theme" of the party, his quick response was "TRACTORS"!!! So, this weekend I will be on a mission for John Deere party accessories!! I havent yet decided how I will do the invitations. Here are the main decisions I need to make:

-location:

-food served:

-invitation:

-theme: John Deere

-cake or cupcakes:

-date & time:

Yikes! i better get to plannin' if I wanna stay on top of things!