Move the lead character and the pointer in the menus. On the Switch, use and to run or for the same thing.
Enter
Confirm choice in menus. Attempt to use/activate the item in front of the character (open chests, climb ladders, etc), or talk to an NPC.
+
Opens the menu.
0 or Ins
Back one level in menus, or close the menu in question. Outside of the menus, hold down to make the character run (not available in Overworld).
. or Delete
Toggle between Equip and Materia screens. In combat, makes the command menu disappear temporarily so you can check your barrier gauges.
5
In world map, changes map display. Pauses during battle.
-
Outside of combat, shows a hand pointer above lead character's head, and shows exit markers. In combat, toggles target name window.
9 or PgUp 3 or PgDn
Move the pointer up or down one page in the menus, or rotate view in world map. Hold down both to escape from battles.
7 or Home
Changes camera angle on the Overworld map.
1 or End
Changes camera angle on the Overworld map. In combat, shows targeting aid.
Additionally, if you press the left stick, it will speed up three times as fast. Even in battle. Press the right stick the enhance the battle and pressing both disables random encounters. You can reverse them by repressing the corresponding control sticks that turns it on before.