Help with sliding down hills

Hey, I want to make a sledding game sort of like a 3d version of linerider. I can’t seem to figure out to make my sled slide down a hill without it tipping over. I want it to slide down a hill using gravity in a certain direction, but not be able to flip over unless it hits a bump. I’m not looking for anyone to do any of the coding for me, if you could point me in the right direction that’d be awesome!

also, if my sled lands at a certain angle, I’d like it to crash.

If your sled is flipping over a bit too easily, consider adding a little bit more mass to it to make it a little more stable. As for checking for a certain angle, you can check the gameObject.transform.eulerAngles and see what the angle is on a certain axes.