I can do better than most, but at the same time worse than many other players. I currently have a 1.0 or 0.9 kda, and I struggle to keep it at that. I want to know, what helps in Arena? Accuracy? Movement? Grenade tricks and combos?
I love topics like these when I can help people out. So here’s my advice. I was Champ 5 in Solo Q and Champ 1 on a smurf in 2018. What I highly suggest is first off get down strafing and gunfights. It’s obviously essential. Time power ups. OS and Camo are at 2 minutes. These can sway the game easily in seconds. And of course there’s movement. It’s huge in H5 and must be nailed. Practice spring jumps and normal comp jumps you would use in game. Spawns are also a big part. Go in forge and memorize the spawns. When I play, I know where everyone will spawn based off of where my teammates far. Enemies will always spawn farthest from the enemy in Slayer. In objective you can obviously spawn trap. Basically get these things down, nail them, and put them to work. See you in infinite 
Id just find a way to stick with a team mate, most people get gunned down when they are far away from the team