do yourself a favor and watch these videos. if you pay attention, learn it and put all of this into use regularly you WILL get much better at Battlefield. guaranteed. these video's were done in Battlefield 3, but just about all of is still applicable.
one thing i want to talk about briefly is utilizing the Game DVR on XB1 to your advantage. now that you can simply say "Xbox record that" you should use it to your help you get better at the game. instead of saying "oh that's fucking bullshit" or "how the fuck did he get me" and getting frustrated say "Xbox record that". when you get done with round go and look at the clip and analyze what you did wrong. now watch that clip 5 more times. burn your mistake into your mind so next time you don't make it. this can apply to any game but i think it will be very useful in Battlefield 4. give it a try. what's the worst that can happen right? onto the videos.
in this video Jackfrags covers reviving. the only thing i want to add about reviving is now in BF4, you have to charge your paddles for a 100% health revive. my suggestion is this - the only time you want to charge the paddles is when the area is clear and you won't be putting yourself in danger. in a firefight, get the revive and throw down some health immediately. get used to reviving and quickly throwing down health until it's burned into your mind and you find yourself giving health even after a fully charged revive.
these are two great videos from Levelcap about cornering and surviving. again, these are things universally applicable for newbies or veterans alike and again, pay attention and put these tips into practice and you WILL get better. guaranteed.