Welcome to a great sport. As for clippless vs. pedals, I think most people prefer clippless. For me, I like feeling connected to the bike since I am not a racer and have never worried about my power output, etc. You just need to practice a bit with them in a forgiving area (eg, grassy) as you get used to clipping in and out. I think the learning/comfort curve is short, especially as you have used them before.
I am president of Greater Houston Off-Road Biking Association (GHORBA) and we have rides (open to all) at various trails around town and some out of town, which is a good way to get to know the trails and meet other bikers. The Anthills is well used and we have riders in our club at all levels. On 9/8 we are having a beginner's only ride at Timberlane trail. On 9/15 we are having an all levels ride at the Anthills. See our calendar at ghorba.org for details as well as locations of other trails in the area. GHORBA also offers skills clinic for its members, which is a good opportunity to learn some basics to build your skills on..the instructors are excellent. Bill