did you start at 100 or 400 Elo?
i started at 400 or 800 i don’t know anymore
You can go back to your first game to find out. In your case, your first game was a bullet game. Based on the rating change resulting from that game, you must have started at 1200 in bullet chess.
Based on your first game, you started at a Chess.com rating of 100.
By the way, a Chess.com rating is not an Elo rating. Chess.com ratings are based on the Glicko system. See How do ratings work on Chess.com? in the Help Centre.