Way to go! You’ll figure out turning too. Just keep doing what you’re doing. That’s the only trick to it.
Awesome! Now that you’re riding the length of the tennis court comfortably, it’s time to move to a larger practice space. A big empty parking lot, a neighborhood road that isn’t too busy, a long paved trail, anything that doesn’t have a distance limit. Use the trunk of your car, a fence, a mailing, a tree, etc. to mount and start riding, then go off and ride as far as possible. Congrats, it looks like you’re doing great!
I really like your description!
Constant fun, exhaustion and then pizza, could it be any better? 
Best regards,
Sanne
Yes, and from the picture of your practice area, I see a huge parking lot…perfect place to start expanding your horizons… you are right next to your comfort zone, and can go back to it quickly if needed. It helped me to try new flat places to ride as much as possible to shake things up. Even though every place was flat, and therefore the same, my brain experienced each new place as different, and therefore a challenge. But, I also have said that if you were to change only the color of my unicycle while I was learning, I would struggle to ride for a few minutes.
Awesome, Leafcutter! 