I started iron 2 at the end of e1a3 and got to immortal by e3a3. Part of it was making my setup better (swapped from my macbook to a PC), but the main part of it is getting the feel of the game and how to aim within it. Walk around different maps by yourself swinging every angle like there is an enemy there and having the crosshair placement to one shot them immediately. Part of that comes down to reacting to their movement or off angle (Aim Lab: VCT Split Angle Hold and Microshot help for that), but learning map sense and mechanics is going to be your best friend.
edit: I should also say that valorant was my first PC FPS. Only other experience is minecraft and xbox OW.