Here are a couple of things you can try, assuming you didn't get it wet or drop it ...
Do a battery pull to reboot. While the device is on, pull out the battery for about 20 seconds, put it back in and let it power back up.
Try adjusting your trackpad sensitivity. It should be in your Options menu.
If these two things don't work, it's possible you have a defective device and may need a replacement.