K.B.
I just held my first 5 year old birthday party in April. It went very well. We had them come from 10:30 to 1. When deciding a time, it seemed long, but was perfect. THey came and we decorated gift/goodie bags with stickers and markers. Then I had game stations throughout the room and everyone went to a station and played a game. Everyone got a prize after each turn at each game. We had hot dogs and chips, then cake and ice cream. By the time we opened gifts and they played more games, it was time to go home.
The key was that I had 4 moms working with me. We had two for games and one for food. The fourth managed the little sisters that were there with their brothers. My friends each brought their kids, two each. Otherwise I left it open for the kids we invited. We had 14 kids total, not counting the little sisters. All parents just dropped them off and picked them up. We had a great time. Enjoy it. It goes by fast. Pretty soon they won't want little parties at home anymore. Good luck!