I'm not a fan of showcasing so young. I felt like we got my son out there too soon, and it undermined his confidence a bit. I guess if a kid is a real blue chipper it wouldn't have the same result.
The early high school years are for getting better, stronger, bigger. IMHO.
That being said, many showcases don't charge to watch, if you want to see one. The formats don't seem to vary all that much, so once you've seen one, you will have a good sense for what goes on. Lots of waiting.
If I had it to do over again, I would take my son to see college games at various levels (DI, DII, DIII) during his early high school years. This would have been helpful.
Good luck.