100% beautiful riding. I’m a 12 year old Aussie trying to save up for a Kawasaki klx140r and have fun and it’s just like a craving moment for me to buy one
standing on the bike makes your weight shift from the back end to the middle of the bike, doing so makes it so that the front and back wheels have the same amount of suspension being used. When you are sitting down your weight is towards the back of the bike making the back suspension carry more weight and compress more than the front, when that happens it makes it so your front wheel can go over things easy but when you go over something (such as a rock or tree branch) the bike suspension has to throw the bike's weight and the rider's weight up and beings that the suspension is already compressed most of the way there is no absorbing of the bump. Like Joseph said when you are standing just grip the tank/seat and you should feel pretty safe so that you can relax.
Also, not changing gears tends to be not healthy for the bike, having the RPMs too high at all times do to not changing gears obviously puts a lot of pressure on the bike. I would suggest riding a little bit more open areas so that changing gears becomes second nature, once you don't have to think about them your riding skills will be 2x better.
Learn to listen to your motor. You need to shift more. Shifting can help keep your motorcycle in the sweet spot of its power range when you learn how to use your gears correctly.
instead of relying on your hands for your stability, scoot up on the seat right above the gas tank and squeeze your legs on the bike, that way you can put your elbows up higher and not needing to firmly grip the handlebars, you can just leave them loose. this takes some practice but will definitely help your riding. (and your hands.)