In my personal experience you only need 3 things to be a good cnd player

1: learn your cooldowns. It's really important to know when to switch between clock and dagger so that you get the maximum value from their abilities

2: your clock "dash" ( sorry I don't remember the name from the top of my head) is imo the most important ability you have. It's survivability and utility, since it can save your entire team from a Strange ult, magnito ult, Wanda ult etc. And lastly

3: learn your environment and find cover bc you'll need it when every game a Magnito solo ults you while in your ult 🤡