In first place, he realize there wasn't plenty of food, so he could have thought in making extra food, just in case something like that happened.

Then he forgot the sodas on the freezer, but he could put the sodas in a ice bucket, instead of put it all on the freezer, it would work for the drinks too. Because if had bought ice bags, the people would have ice for their drinks.

He have invited too many people, so some people stay without a place to seat. Next time it's better think twice about the number of guests.

And Bryan was so excited about the party, the he completely forget to install the estéreo. He invited Kirsten and Beth to the same party, what he knows was a completely mistake.

He should be consider to make a list of things to do, before start a party.