I wouldn't worry too much about making progress, any time in the car will help. It varies from person to person but it normally takes 30+ hours before you're ready to take the test and it doesn't really get any more enjoyable during that period, you just have to power through really.|
Once you've taken the test, got a car and driven about for a couple of months then you might feel comfortable.
I'd recommend sticking with it because when I started learning I got to about 20 something hours and my instructor helpfully decided to stop being an instructor and I was too lazy to organise another one. I waited two years before starting again and ended up having to take a load more lessons than I probably would have needed if I'd just carried on.
So my point is if you give up and decide later to carry on, it could well cost you a lot more time and money.
Level 37 Social Justice Warrior