It's good to be able to unclip with either foot (e.g. if you need to make a panic stop in the middle of a tight turn when you're leaned the opposite direction of the side you usually unclip. DAMHIK ).

But that's an "intermediate" skill. Get to where you can reliably clip in and unclip with the foot you prefer, however long it takes you, THEN start practicing occasionally with the opposite foot. You'll develop better muscle memory and instinctual habits if you have a "go-to" foot, IMO.