I agree with others, this sounds right. I was just coaching my son through this the other day, as he is growing fast and I had to raise his seat again. The best way to start off is to get the left pedal high, right foot on the ground, and simultaneously stomp on the left, and use that as the 'stepstool' to get yourself up onto the seat -- then continue pedaling with the right. The whole time trying to avoid the front wheel turning a lot. Sometimes it works out that when you stop you can put your right foot on a curb, and remain seated, just leaned over a little bit maybe. (all that can of course be reversed mirror image, just swap left<-->right)

Your goal when riding is to not quite completely extend each leg at the bottom stroke. If your heel can just graze the pedal, then when you put the ball of your foot on the pedal (which is how you should ride), then it should be just about right. If you find your hips are rocking back and forth, then you're a little high, and should lower the saddle a cm at a time until the rocking stops.