Thanks to all the advice on here about learning how to jump. See my thread here: How do I ride up seemingly impossible hills?
Since then, I went to the trails yesterday, and I jumped that steep hill with the tree root at the top! I built up my confidence and momentum, then right when I was about to hit the root, pulled up on my handlebars and I cleared it! I had to let out a loud "Whoo hoo!" After that, powered through the rest of the trail and didn't stop once over any hill. Also that day jumped over my first tree log! It was like a foot high. Once again stayed in a low gear and smoothly pulled up and over with ease. I love it!!! I continue to be amazed how I can easily spend 3 1/2 hours of pure fun getting to know the trails and testing my endurance and getting a full body workout. But amazingly it's not even about the workout! It's just hours of fun!!!
So, given that I finally cleared the hill/root and log, I went through a few trails that I probably shouldn't have, and have the scars to prove it. I fell once, and had to "hike" up a few cause I just couldn't handle powering up one hill right after the other and then multiple root-step hills. But I'm glad that I am getting a feel for them.
Also, when I first bought my bike and rode it around on the street a few days the saddle had my rear HURTING... So I got a wider one. But after going to the park and being off of it most of the time, I see why it comes like that. I can't lean back on my seat cause it's so wide that my legs get caught on the wide part. So eventually I will put the narrow seat back on.
Again, thanks for all the advice on here, and I am learning so much! I think for the second time riding I'm doing good, but have much more to learn about gears/brakes to really get the most out of the trails and my bike.