Rogue Legacy 2 is a roguelike game, so you will always have to start from the first biome and work your way through to the later ones. The only way around this is to pay a fee to prevent the world from resetting between runs, in which case your map will still be unlocked from the previous runs, and you can teleport to wherever you'd been prior. The only way to keep these teleporters open to future biomes is by finding the NPC Maria, aka Pizza Girl. This Area Teleporting Guide will tell you everything you need to know about this fast travel mechanic.
Before you can unlock the area teleporters in Rogue Legacy 2 you need to clear Citadel Agartha and travel to Axis Mundi, there you need to progress far enough that you find a door advertising Pizza Mundi. You will find this door in the upper right of the map's background and when you enter it you will be able to talk to Maria, the Pizza Girl. Once you have spoken to her, exit the Pizza Mundi and go to the door north of that room. This will take you to the Sun Tower where there will be a teleporter. Normally these allow you to teleport to different teleports in the same area but if you pay a fee you will be able to unlock teleporters in other areas.
Maria will charge you gold for unlocking the teleporters, the first one you unlock is the Axis Mundi teleporter which costs 1,500 gold with subsequent ones in other areas increasing in price. Although they are expensive it is essential that you purchase them as they give you the ability to immediately travel to where you need to go without losing health or mana getting there. This will help you to get closer to completing your objective and getting through The Golden Doors.
Take a look at our Beginner Tips and Tricks to get help in Rogue Legacy 2.