First, you want to see if anyone nearby plays the game. If you can find another small group of friends who play melee, then your group size just doubled.
The only way to do this is to advertise, so do whatever you can to make your goal known. Make a facebook group, advertise tournaments or gatherings on instagram, whatever you can in order to make sure people who WANT to know if there's smash in your area do.
Once you've either gotten a few more people or decided that finding more people is impossible for now, start recruiting people. I don't know what you're schooling situation is, but if you go to a high school or college then bring a setup with you one day where there will be people passing by, and play some friendlies with whoever you know plays melee. If anyone asks to join, let them play immediately, and then if they seem interested in the game tell them that you're starting up a competitive melee scene. If you don't go to a high school or college, you can do the same at basically any social gathering. Make sure you've looked for people who already play the game first, though -- the more people you have playing melee with you already, the easier and more convincing it will be.
I can't write out a more detailed response right now, so I just gave some general pointers, but I hope that helps! Keep in mind that there almost certainly are people who already play relatively close to you (within half an hour away by car maximum), probably more than you think.