Newbies play hesitantly. It’s only natural, but it can also get you killed (sitting duck syndrome) or allow great opportunities to slip away.
Always have your marker cocked and ready to go – you may only have a second to make that beautiful, sure shot.
If it looks like a good time to run forward, do it! (Unless someone is waiting for you, a running target is a tougher target, anyway.)
If have the chance to go for the flag, take it. You might not get another chance later on.
Act, act, act! It’s the only way to learn and improve your game. Yes, occasionally this might get you killed, but you can try again in 5-15 minutes. And sometimes, it’ll make you the hero.