You might want to start by watching several videos on youtube, anything to do with ArtCam or Aspire would be recommended. Not that they are the only packages out there but they are very popular especially in the Sign industry. You will find all kinds of videos up there showing you how they develop a design in the CAD/CAM software and then they will show you the process of cutting out the sign. Some signs are cut out of wood however many for commercial customers are cut from high density foam, which is more expensive but does not warp, crack, or get damaged in snow or rain. Anyway, I have not seen a trade show targeted at sign makers but there clearly could be one. There are shows and training sessions in some of those CAM products.