I just downloaded the height map terrain generator from Orbolt https://www.orbolt.com/asset/SideFX::heightmapterraingenerator [orbolt.com] Is there any kind of tutorial to tell you how to use it. I'm a newb and have no clue even where to find the plugin in Houdini. Are there any tutorials?

Thanks

it isn't a plugin - it's a Houdini Digital Asset, the difference may not seen important but it is.
you may want to have a look at this:
http://www.sidefx.com/docs/houdini15.0/assets/ [sidefx.com]

with your mouse in the network try
TAB > Digital Assets and see what is in there….