New to N scale and I only have a little G scale experience.

We just bought a N 51151 4-4-0 steam loco and the front 4, I guess the leading wheels, don't seem to want stay on the rails.  To the point I wonder if they are even intended to and are instead just for decoration.  If they are supposed to stay on the rails is there some adjustment that can help?  They just seem to bounce around...

Many thanks