One of the biggest aspects of Persona Q, which it inherited from the Etrian Odyseey series, is the ability to make your own map of every dungeon in the game and done on the bottom screen of the Nintendo 3DS. Every floor of a dungeon will start out as a blank slate and it will start to get filled in as you explore. However, this only pertains to the tiles and not to anything else that can be placed on the map, including icons, walls and any notes.
Luckily, there is an option in the game, called Auto-Map, which will automatically draw in the walls for the map, making it so you only need to manually place icons on your map. You will find these icons on the bottom right of the bottom 3DS screen, and you can make the map as detailed as possible if you want. The little red thing allows you to make notes, and you can only have a maximum of 32 of these on your map at once.