How do I cope as a new firefighter when everything feels overwhelming?

You are new and the fire ground overwhelms you, and every experienced firefighter around you once stood exactly where you are, feeling exactly this. The chaos, the noise, the speed, it floods you because you have not yet learned what to ignore. That filter comes with time. Right now your job is not to master everything. It is to learn one piece at a time. Overwhelm comes from trying to take in the whole scene at once. The veterans are not calmer because they see more. They are calmer because they have learned what to focus on and what to let fade into the background. You will get there by reps, by showing up, by doing the basics until they stop taking all your attention. Do not measure yourself against them yet. Measure yourself against who you were last month. For now, pick one thing to get solid: your gear, your tools, your assignment, whatever your role asks first. Master that until it is automatic, then add the next. Trust your training and your crew to carry what you cannot yet. The fire ground will slowly shrink from a wall of chaos into a set of tasks you know. Give it the time it honestly takes.