I am still new here myself, but thought I would take a moment to welcome you. This seems like a great forum full of helpful people.
As for the admin allowing you to post with your signature, I thought I would add a few things.
They do have some rules about how to create your signature and I recommend carefully reading through them. (I actually messed mine up at first and had to re-do it).
Then I would just follow basic edicate. You want to be helpful to others. Avoid spamming the forum. Instead work towards creating and adding value.
If you do these things, the admin should allow you to post with your signature without any problems.