Hey LittleBike, I don't think you did anything stupid. Dirt riding is different than street riding. The challenge is part of the fun. It would be better if you had a more experienced dirt buddy to go with you. He (or she) could help with some pointers and tips. (Call for an ambulance if things go horribly wrong)
Getting out there and getting seat time is the only way to practice. Though of course if you really have no clue what you are doing then you might just be engraining bad habits. If you don't have any offroad buddys who can teach you a little, then get some offroad technique videos. Better yet, find a day or weekend school somewhere so you can get some good teaching from a proffessional. A few years ago I did a one day offroad riding school with Rich Lafferty, was money well spent. I'm thinking of doing another one this coming season. I'll bet you have more options out there on the West coast.
Here is my offroad tip for the day. Dealing with down hills and braking. For a long time I my "dirt" riding was only adventure type riding and light dualsporting. I had a few Suzuki DRs 350 and later a 650, even a big R1150GS for a while. For a long time my only real technique for braking on downhills was just shifting into a lower gear and using engine braking. Obviously this can work very well in some situations (and if you have a four stroke bike). When I started doing more hardcore dualsporting and dirtriding I started having to learn how to use my brakes better. I still have a DR650 but now do most of my dirt riding with a two-stroke enduro. The two-stroke bikes have very little engine braking, so I have become much better at using my brakes. The front brake provides the majority of my braking (just like on the street). You just have to be much more careful using it. Learn to be your own ABS. When your wheels are locked up, you just slide down the hill. Learn to use what little traction you have to keep your wheels rolling, then you can still steer the bike.
Sorry to be long winded. Learn to use engine braking, learn to you use your brakes better. Go have fun on more dirt roads and trails.