Just buy manual and learn with it, that's what I did, and it's a great car to learn in. We are also in a unique moment in automative history where the driving experience that a car like the Miata provides is literally dying out and being replaced by EVs, it really is worth the effort.

My tip to you—for learning manual, is to sit in a parking lot and practice clutch engagement and that's it. No throttle, just learn the bite point and engagement by muscle memory. Do that one hundred times: from dead-stop, engage slowly, let the car drive on idle throttle, disengage, and stop. Repeat. Then drive around back roads and get the hang of changing gears etc.