There are many ways to switch spaces. For keyboard shortcuts, check the settings in System Preferences > Keyboard > Keyboard Shortcuts > Mission Control. For trackpad gestures, see System Preferences > Trackpad > More Gestures > Swipe between full-screen apps. For Magic Mouse gestures, see System Preferences > Mouse > More Gestures > Swipe between full-screen apps. You can also go into Mission Control and click on the space you want.