If you're going to university / college (I'm assuming you're graduating high school), you can definitely start some sort of gaming club and include Smash.
I did it for where I live here in London. Unlike the UK, London in Canada is a very small city with no metro line and inconsistent buses. Back before Smash4 was released, someone in my school started a "3DS club" in the university. His way of advertising was genius, cheap, and cost nothing: all members of the club set their streetpass messages to "Join 3DS club!" and we reached to our audience. He's one of my best friends now because of this club.
The club eventually reached out to competitive Pokemon due to the interest. When Smash 3DS was released, I took advantage of the interest in the game and started doing small club toonie tournaments (in Canada, a toonie = $2 coin). The tourneys were very well received, so I kept doing them and saw many players get into the competitive aspect the game offered. We've now moved to playing Wii U competitively, and Smash has now grown so much in London that we've had to make a separate group specific to the city. We even managed to get Wii U monthlies at a local bar that is very happy to have us there.
So if I can do it in my small city, you can do it for sure.