I am using two Spaces on my mojave and I can use
Ctrl + Left/Arrow to change the screen.
But isn't there a way to use only mouse to change the space instead of using keyboard?
Ask Different is a question and answer site for power users of Apple hardware and software. It only takes a minute to sign up.Sign up to join this community
If you use a Magic Mouse, then yes! Head over to System Preferences > Mouse. You will find an option there to set it to a two finger swipe to the left/right.
For other mice, ususally no. Some mice, like Logitech Master support all kinds of stuff though with the Logitech Options. A workaround would be to set a Hot Corner (System Preferences > Mission Control > Hot Corners), then you don't need your keyboard, but it'll take longer.
I read in the comments that you are using Logitech, so with Logitech Options installed (install link here), you can set mouse gestures to switch Spaces left or right. You can also set the secondary scroll wheel of the MX Master 2S to do that.
I recommend you also activate smooth scrolling, if possible.