What to do when you start your adventure in Super Mario RPG.
Start a New Game
Super NES Version
To start a new game in the Super NES version, choose "New Game" at the top of the menu, then enter your name, then choose "Done". There will be a cutscene.
Nintendo Switch Version
Press a button on the title screen. If you've never played before, you will be asked if you want to play in Breezy mode or Normal mode. Breezy mode causes battles to be easier, and is intended for those who want to focus on the story. You can change this in the settings at any time, but the game will warn you that you can carry fewer items in Normal mode, so switching from Breezy to Normal could cause you to lose items.
In the Nintendo Switch version, if you already have a save file, you can press a button on the title screen to show your save slots, and your latest autosave. You can press Y on a save slot to delete it.
Go northeast and through the door. Continue going northeast and you can battle the Terrapins that patrol the hallway (or you can just walk past them). During battle, if you choose Attack, and press the attack button again just before Mario's punch lands, your attack will do more damage. In the Nintendo Switch version, there is a visual indication of when to press the button to get a boost, and if you do it successfully, you will do some damage to surrounding enemies as well. Also in the Nintendo Switch version, enemies are added to your Journal after you defeat them.
Go northeast and you will have to battle the Terrapins guarding the door. If you press the attack button just before the enemy's attack lands, you won't take as much damage. Again, the Nintendo Switch version shows a visual indication of when to press the button to reduce damage.
Go through the door. Cross the bridge, and it will collapse behind you. Go through the door.
Go northeast and there will be a cutscene. Then you will battle Bowser.