Thing is, if you get the right bike, you will feel comfortable and confident ....it might take sitting on a few to find 'the one'
You're a couple of inches taller than me, so gives you a bigger scope - my only word of advice is make sure you can get both feet flat - it makes so much difference
I bought a bike, had the seat scooped, but it was the wrong bike, then found this one.... Love, love, love it, and feel just as confident on this as I do in the car, even though I've been driving for many more years.
Take the lesson, see how you feel, is there any timescale to the lesson?