I have no idea how to play. Literally just mashing buttons right now. Never played a smash game before.
Can someone point me in the direction of a tutorial that can show me how to play the right way? Good beginner characters, etc?
You have two buttons to attack: One button is for normal attacks, and another button is for special attacks. You can modify these attacks with different directions, at different times.
For example: Most characters can hit once, twice, three times by simply standing in place and hitting the normal attack. If you run and hit the normal attack while running, they'll do a dash attack. If you push forward and hit the normal attack, they'll do one attack. Tap up and attack, and they'll do another. Tap down and attack, and they'll do yet another.
Same when in the air: Tap attack while free-falling to do one move; push forward and attack while in the air to do another; push back and attack while in the air to do another; and so on. Different moves have different properties. For example, some characters can launch airborne enemies downward by jumping above them and tapping down and attack.
The more damage one takes, the farther they'll fly when hit. If you hold toward the stage when hit yourself, you'll reduce your knockback and survive longer!
You can charge moves on the ground, which is called a Smash Attack. Thrust left, right, down or up and HOLD that direction while tapping the attack button. Your character will flash, charging up. When you release, you'll hit with huge power and knockback.
As for special moves, these are moves like Mario's fireball (neutral special), cape (forward + special), watergun (down + special) and coin punch (up + special). Most characters can jump twice, and use their up special for a "third jump" that helps them make it back to the stage. So when you're knocked off the stage, jump once, jump twice, then use your up special to get back to the stage.
Also, you can use the shoulder buttons to create a bubble shield that blocks most hits. You can grab others in this state by tapping attack. They can also grab you when you're shielding. Once you grab someone, you can tap left, right, up or down to throw them in that direction. While in your bubble, you can also roll left and right by tapping in that direction. This allows you to safely dodge attacks. And in the air, you can tap the shoulder button to dodge there, as well.
These are just some beginners' tips, applicable to most characters. I hope it helps! There's also a tutorial video on the title screen, if you just wait a moment when you first boot up the game.