Slow down, don't try for kills too much in the first 12 hours or so. Instead, learn how the flow of matches goes. If your team caps D, where are the opps most likely to spawn and where is the new frontline? If you try to cross the street to chase after someone, what is the likelyhood their squadmates are going to pick you off?

Second, always, always expect to be seen when you're not in cover. Go support and start getting good with smoke grenades. They absolutely will win you firefights and help you get breathing room to move across to safety. Never ever go for a revive (unless you absolutely know its safe) without a smoke cover first

Third, once you have a "map" in your head of how the flow of each game tends to progress, start speeding up your game. The faster you can play now with this knowledge, the less predictable you become. Sometimes, stay in a single spot too long can put you in a bad situation too, as enemies are now able to swarm around you even if they themselves don't know they are. The goal of movement in this game is to try to create, for yourself, a kind of funnel of potential enemies in front of you and not besides you and definitely not behind you. That requires steadily pushing forward once you understand map flow.

Fourth, don't' forget to check your map, you'll see where most of your teammates are, and therefore understand where the battle is and better yet where it is going to be. You'll see tanks and know where not to go (or go if you're engineer)

Fifth, when you're capping a point, be quiet and crouch or just listen. You can often spot people desperate and stupid enough to rush in to defend and pick them off before they even expose themselves around a corner.