In previous years, Nintendo has held a "Play Nintendo" event to showcase upcoming games in a public setting. In addition to being like an E3 that most people can actually visit, the kiosks are full of Nintendo charm and glee while also offering demos for upcoming games. I'm not sure if that is really needed (the internet is great for downloading things!), but maybe some people aren't sold on a console; an event like this will give them the chance to experience that device to its fullest potential.
With a slight name alteration, the Nintendo "Summer of Play" tour will be kicking off next month with dates around the US for the entirety of the season. Starting in Irvine, CA and ending in Baltimore, MD, the tour will have demos for a bunch of Switch and 3DS games (that, by the end of the tour, will already be out in stores). If you missed the Splatoon 2 Global Testfire or really just want to play Arms a few weeks before launch, this is your chance!
The games included for this tour are Splatoon 2, Arms, Mario Kart 8 Deluxe, Snipperclips, 1 - 2 Switch, Ultra Street Fighter II, Zelda: Breath of the Wild, Super Bomberman R and Minecraft: Switch Edition on the Switch while 3DS titles will feature Hey! Pikmin, Super Smash Bros. for 3DS, Miitopia, Pokemon Sun and Moon, and Super Mario Maker for 3DS. The dates are below.