Hi! I'm sorry to hear that you've been having difficulties with applying. As is stated in this link: https://mcpz.net/threads/applying-for-helper.33861/ you must have a set of requirements filled out before applying. Therefore, I'd double-check beforehand.
However, from what I see, you fill out, if not all, most of the requirements checked off. In this case, the problem you are having could be that you have applied beforehand and either got denied (in which you must wait at least 2 months before applying again) or you resigned from the Staff Team. In this case, use this link: https://mcpz.net/index.php?applicationform/15/form as it will bring you to another application that you will be able to fill out successfully.
If you have any more problems after this, feel free to post another question or just privately message me or another staff member. I hope this helped!