anyway to connect to a mac mini with wireless mouse

What wireless mouse do you have...?

An older Apple AA battery mouse will require using a USB mouse to setup and pair the wireless mouse.

A new Apple rechargeable mouse should connect when you connect it to the Mac mini with the charging cable.

No. Mine is very old. LogicTech M325 wireless optical mouse. It comes with a USB receiver which plugs into any USB port. I plugged this one into the keyboard USB port. The transmitter looks like any ordinary mouse. It looks exactly like this one.

I do this everyday. A long time ago..., with my previous Mac mini, I bought a wireless logic tech mouse. When I updated with the newer Mac mini, I kept this same old mouse. The only problem is sometime I have to replace the batteries.

What Logitech Mouse...?

Are you using a Logitech USB Unifying Receiver dongle...?