I’m a noob as well. I just started this summer, so I know how it feels like. At the moment my longest runs are a about a mile, but I still can’t free mount :o I’m going to tackle that next.
Give it a try! As soon as you can let go of the fence, wobble a couple of yards and hop off safely, try it outside. Every time as you are done practicing and leaving the court, grab a lamp post or a traffic sign pole and go for it. It will feel very different from the court, but you have to get used to it.
Otherwise you will develop a comfort zone inside the court and great mental barrier for the outside. You won’t ever feel “ready” for the big world. This was happening to me, when I realized I have to try the pavement someday. Should have done it way earlier. Don’t worry if you can’t turn yet. Your first runs on the pavement won’t be that long anyway 
I got a 20" no-name unicycle as a present. The seat was horrible! Nevertheless I started with it. As soon as I was convinced I just might be able learn this unicycling thing, I ordered a longer seatpost and a Kris Holm Fusion Freeride Saddle. That was what the salesperson recommended as the most comfortable seat at the moment. It feels sooo much better! I have never tried (or even seen) an air seat, though.
Now I have a 26" uni as well, which came with a Viscount saddle, but I like the KH so much better I switched the KH on the 26" and the Viscount to the 20" uni. (I am still practising new stuff on the 20". The 26" uni feels like a freight train compared to the 20".) I have now three saddles and I can tell the saddle does make a difference.
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