Picking up TT tomorrow, size ball?

This is not my first rodeo in towing a trailer. Towed boats, closed box trailer, etc. I also had Class A and 35ft fifth wheel. This is my first TT. I just need to be sure, so I can take the right hitch with me to the dealer 3 hours away. I do have a brake controller.

And no, I will not be using WDH and Sway controller at this time. I already had the discussion about WDH and sway control in my other post few days ago. No need to go through this again here in this post.