Is it a new macbook?
Using an old mouse:
Yes and no.
The macbook only has 1 USB C port.
If the mouse is wired (USB A), you will need a dongle for a conversion.
Only one spot for that dongle to go into to... the USB C port needed for charging.
And some off brand dongles w multiple ports I hear thwart the charge... sooo.. I dunno.
This is a product that pushes wireless technologies.
Do you need a mouse, like the topic says. No. It has a trackpad