New Mac mini set up.

A USB mouse will make setting up the new Mac mini easier.

In fact, having both a USB keyboard and mouse handy will make troubleshooting easier with some problems you might eventually encounter with your Mac.

Just about any USB mouse will work.

That depends on which wireless mouse you have?

If you have the older AA battery mouse, then you will need a USB mouse to get setup and connect your mouse.

(FWIW most any USB Generic or PC mouse will work)

If you have the new rechargeable mouse, then it should automatically connect when you plug it into the Mac mini.

Another option might be to use the Mouse Keys, but I not sure if that will work during the initial setup.

see > Control the pointer using Mouse Keys on Mac - Apple Support