Good advice TR. There are two types of showcase events. Pro Style Tryouts where you run the 60 , take ground balls , fly balls , here you show your fielding ability , footwork , approach to the ball , hands and arm strength. Batting practice where you show the ability to barrell the baseball on a consistent basis , bath path , bat speed , approach , power etc. And bull pens where pitchers are gunned and show command as well as velo.
Then there are showcase events where you play games or a combo of both pro style work outs with games as well.
In a pro style work out your not going to stand out unless your tools stand out. Speed , hitting ability , fielding ability , arm strength. In a showcase where there are games you stand out by showing you can actually play the game and play it well.
Some kids are not going to stand out at a pro style work out because their tools do not stand out above the rest. Some kids stand out at a pro style work out because their tools stand out above the rest. There are kids that have tools that cause them to stand out but they do not play up to their tools. And then there are kids that do not stand out for their tools but play above them. And of course the ones that have tools that stand out and also play up to those tools in game situations will be the ones that every coach will want to write down their name.
Just go play. Let your tools , talent , work ethic , attitude , speak for itself. Good luck