Everyone is invited to party?

That's a great start! To make it a complete sentence, you need to add a little more information. Here are a few ways you can finish the sentence:

* Everyone is invited to the party? (This is a question, asking for confirmation)

* Everyone is invited to the party! (This is an exclamation, making it clear that everyone is welcome)

* Everyone is invited to the party on Saturday. (This gives more information about the party)

Do you have any details about the party in mind that you want to add? I can help you create a complete and inviting announcement!