U is for Undecided
Undecided people aren't sure what their gender and/or romantic & physical attractions (if any) are. Sometimes called “questioning”, this is totally fine, and there is absolutely no rush or obligation to “figure it out”.
Remember that your gender & sexuality belong to you, and no one else gets to define either of them for you.
Respect people who are still figuring themselves out, or who know who they are but aren’t out yet, regardless of their reasons!