650C vs 700c gearing

[OakLeaf]

I just went back and re-read the OP also, and "if I could touch the ground" is a big red flag.

If you can touch the ground without leaning your bike over, on a road bike, then your seat height is too low. You'll never be able to pedal efficiently if you're not extending your legs, and even a very low cadence may well feel "out of control" if you're having to hyper-flex your knees and hips on each stroke. You don't want your knees fully extended at the bottom of your pedal stroke, but mostly so. A quick and dirty test is to set your seat at the height where, at the pedal's lowermost point and your leg fully extended but NOT clipped in, your heel just touches the pedal at the spindle center. Then when you move your foot back into pedaling position, there will be a slight bend in your knee. An illustration of some bike fitting basics is here.

If you've been riding with your seat much lower than that, then don't change it all at once. Small changes make a big difference in your biomechanics, so let your body adjust gradually. Raise your seatpost at most 3-4 mm each ride. Take as many rides as you need at any given seat height to adjust to the difference, before you raise it the next increment. Get comfortable with leaning the bike over when you come to a stop. Turning your handlebars slightly away from the foot you plan to touch down with, will help initiate a lean. While it's good to be able to touch down with either foot, IMO you'll have a smoother learning experience if you make a habit of always putting the same foot down, so you don't experience a moment of indecision. Then once you're completely comfortable and habituated to that foot, then you can start learning to put the other foot down instead.

Now, if I've misinterpreted what you meant by "touch the ground," then sorry for the misunderstanding ... I know that's the same phrase I use about motorcycle seat height when what I mean is that my leg strength and angle won't support the bike if I lean it over far enough to touch the ground, and/or I won't have enough straight line traction from the rear wheel to get it back moving again ... still it would be extremely unusual for a bicycle frame to fit your upper body properly, yet be so tall that your wheel is at any extreme lean angle when you're at a stop ...