What kind of hot dishes should I serve at my Daughter's graduation party?

Penne ala vodka, baked ziti or eggplant parm.

Any hot pasta dish is always a good option. Don't forget the green salad.

what I eat at a party all depends on WHEN the party is.
Not all parties take place at mealtimes. Those that do not occur during a typical meal time offer less food and more snack items.
I personally would not do a hot dish...you have to keep it hot and depending on how many guests you have, that could be hard to do. With the list of food you already have, I wouldn't even bother with a hot dish. You already have 3 meat items and 2 sides. No more necessary. Add some nice variety breads/rolls for sandwiches and you are good to go.

I would suggest baked lasagna,slow cooker recipes which will be warm throughout the party, and hot finger foods as empanadas, baked stuff mushrooms, baked brie, pigs in the blanket, etc.

Do a simple pasta dish like spaghetti, you can do some chicken maybe fried or just grilled with awesome seasoning like oregano yuum, meatballs is a great idea as well! everyone loves meatballs.
Even a lasagna would be nice.

Maybe grilled chicken? It very versatile. People can put it in a salad, your daughter can have it in a sandwhich, or you can jut eat it plain

Mac and Cheese
Vegetables
Any Pasta like spaghetti and meatballs
Cut the Italian sausages into tiny bits and put a pick on them.
Alfredo with broccoli mixed in