Blackwind

Fast Travel is essentially this game's Level Select. From any Upgrade Portal, select Fast Travel and then the Level you want to move to (obviously you can only move back to previously completed Levels). You will need to use this at some point to get back to the first couple of Levels to collect Skins that were locked in regions you couldn't access initially, so there's no rush to use this, but if you want to get this out of the way, you can get it as early as the Mining Facilities Level.