I would recommend start by learning how to make good knives. The Complete Bladesmith by Jim Hrisoulas might be a good primer. Making good knives would be in line with a small coal forge. You can learn a lot about moving metal around and heat treating on smaller blades that will serve you well as you work your way up to larger one. You also need to figure out what sort of swords you want to make and if you really want to forge it or stock remove it etc. Creating a katana is a different setup and skill set then the ones used for creating European style swords.