You set yourself up for rejection. She might say no.
You imply that she would be doing you a favor by going out with you.
You imply a formal date. You are making a move on her. The pressure is on her.
If she says "no," you are never sure whether to ask her again for another time. Was it, "No, I don't want to go out with you," or "No, I want to go out with you but I'm busy that night."
You literally sound like a junior high kid asking a girl out on his first date.
The right way to ask a single girl out is, "Let's get together and do something sometime." Memorize these words. By saying this, you give an impression of a casual meeting. No big deal. Friends getting to know each other. Not a formal date. If you say this, her response will let you know whether she wants to date you or not.
How to ask a girl to homecoming?
If she does not want to go out with you, her verbal response may be "no" or it may even be "yes" to save your feelings, but her tone, her facial expression, and her desire to drop the subject will let you know she is not interested. Don't pursue it further.
You are not set up for rejection. After all, you have not really asked her out. You've made a statement.
You are throwing out an offer. The implication is that you are doing her a favor. She is not doing you a favor by going out with you.
It implies a casual get-together to get to know each other, not a formal date.
You aren't asking her. You are making a statement which says something about you. You are the type of person that likes to do things with friends, and of course she would like to participate. After all, there is no pressure. You are a confident, friendly, fun-loving person who is doing things.
Now re-read that phrase. "Let's get together and do something sometime." See how much better it is than asking a question that may get you a wrong answer?