If you want to stay wireless, then a Bluetooth mouse would be a good option. Bluetooth mice can be just a bit laggy. They would not be good for games, but probably fine for productivity work.
Now for some great news. The Surface Pro 8 has 2 Thunderbolt 4 ports on it. Thunderbolt 4 uses the newer USB C connector standard and is much more powerful than traditional USB. For example, with the right adapter (usually called a "hub" or "dock") you could connect 2 4K monitors to the Surface Pro 8. Of course, you could also plug in a lowly USB mouse to the Thunderbolt 4 port with the right adapter but you would be wasting the power the Thunderbolt 4 port offers.
So, the key here is finding the right adapter for you. Broadly speaking, you want a "Thunderbolt 4 Hub" of some sort if you are wanting to take full advantage of Thunderbolt 4. Since Thunderbolt 4 is so new, you may have trouble finding a Thunderbolt 4 hub that is reasonably priced. I linked the only one Best Buy carries (the Razor Thunderbolt 4 dock).
Some potential traps
* Surface Dock 2. It may work, but it is older - and somewhat strange proprietary tech that doesn't follow the Thunderbolt standard.
* Generic "USB C hub" or "USB C dock". You want to see "Thunderbolt 3" or ideally "Thunderbolt 4" on the specs. I know it is confusing because Thunderbolt 4 requires the USB C connector. But USB C is not necessarily Thunderbolt (the other way around). That said, depending on your use case, a USB C hub (like the linked Insignia) would technically work and would likely be much cheaper than a Thunderbolt hub if all you want is old-school USB ports or other older equipment.
* For me anyway, the connector cables on 90% of the hubs are much too short! Why are they only 6 inches long usually!? If you are looking for something portable, then a short cable may be fine, but in my case, I would be looking to HIDE the hub somewhere out of site on my desk - in which case the short connector cables are a no-go. Again, you have to consider YOUR use case.
Hopefully this helps you out. Full disclosure, I don't have a surface pro 8 but I am a long-time user of Thunderbolt and USB C.