How to support outdoor gas pipe?
If possible it is better to bury it to avoid exposure to the elements and damage from miscellaneous things. Having it above ground is no problem though as long as it is firmly supported. You don't say where you are, so without knowing the climate, there is no way to know how to support it.

One simple way to support it over soft ground is to drive a long metal rod into the ground, like a grounding rod, weld a split ring hanger to the rod, then fasten the pipe in the hanger.