Is it better to use a Mouse with macbook Pro 2020?

That is entirely up to you.

I'm not overly fond of trackpads, and prefer trackball optical mice, but your mileage may vary.

You can try out the trackpad for a while and see how you get along and then decide whether you'd prefer a mouse or not.

You can switch back and forth as required even if you do decide to get a mouse.

Not sure which mice you are looking at. Most Bluetooth and USB mice (with an adapter) should work on a Mac. Including the current 2020 models.

The current $79.99 Magic Mouse 2 available on Apple will work with the current 2020 13" and 2019" 16" MacBook Pros just fine.

Buy Magic Mouse 2 for Mac in Silver - Apple

Where are you seeing lack of compatibility exactly?

I use a Logitech USB optical trackball, Logitech now offers wireless versions though: https://www.logitech.com/en-us/product/wireless-trackball-m570?crid=7

Works fine with all the Mac computers I've ever tried it on.