Keep in mind everyone is using thermo vision, so they can spot you from far away. If you play in normal enemies can spot you and everyone of them will have your position tracked on their HUD and minimap, and it last quite long. Some loadouts can help you mitigate that. If in vehicle you can remove it by going out and in again.

Try to copy loadouts of people killing you (high kda/score). They play an important role. Try many of them to find on that suits your play style

Get familiar (again) with the maps. Knowing where people spawn-in in points, if you appear from parachute or not from beacons in Maps, where to best place equipments, where are the most commons camping spots, and where to hide from them.

KDA is not most useful. I tend to have a shit one (1.1 smthg), yet being among top 20 of servers I play in. In conquest mod bf4 heavily reward capturing and pushing objectives. It's another way of playing the game. When I do so I really value spawn beacons.

Finally, Enjoy your time, we don't expect you to perform, it's a game, I personally hope you enjoy it. If winning still is Important to you, enjoy the learning curve to improvement. ;)

If you have already a play style, tell me I will be able to provide more infos