Hadrien2005

HELP! I was planning on making a server where people can teleport to other worlds, when I finally got the command block to teleport me, I got back to my original world but I was back at the original spawnpoint. I've tried /kill but it says I don't have a spawnpoint when I set my spawn 4 times before I teleported. I had a huge building that I spent a long time on and I don't want to lose all that progress. How could I get back to my building without the exact coordinates, can I get the coordinates through logs or something? Thanks