I've never flown a Speed Pilot (or a plane like it), but none of the responses so far have really answered your question, so here goes... I would definitely try taking off from a paved runway. That would give you more time to see what the plane is going to do, plus give you some practice with the controls while you're still safely on the ground. Second, when you hand launch, don't throw the plane upwards. The plane does not have enough power to climb immediately, and will stall and crash. Throw it nice and level. Actually, "throw" is not the right word. Have someone run with the plane, and gently launch it level. If there's any wind, make sure you launch into the wind. The perfect place to learn to fly this plane would be a nice hill with really long weeds growing. If you launch at the top, it will give you more time to recover if the plane dives at first. The long weeds obviously cushion the crash.

Like AQ500 I have seen folks crash and crash these planes. But I have also seen some finally succeed, so it is possible. The following advice applies to any new skill: "Do something different." Don't just crash and crash without learning. See what happens if you hold a little up elevator as you launch. If the plane is turning before crashing, maybe hold a little opposite rudder. Realize the plane is underpowered (compared to glow-powered trainers anyway), and will only climb very slowly.

The suggestion that you join a club, etc., is a good one, but may not be financially feasible. The club initiation, club dues, and AMA dues for one year will almost certainly exceed the entire price of your Speed Pilot, plus a bunch of replacement parts. However, you may be able to find someone at the club flying site who will test fly your plane, so at least you'll know if it's flight worthy.

Good luck!