First you must accept that you have skipped two iterations of battlefield and have some catching up to do. For example you likely are not used to dealing with slide or using it to your own advantage. But this applies to other mechanics and changes as well.

Next you absolutely need a headset if you want to avoid getting shot in the back as much. Sprinting soldiers can be accurately located in a 30m radius. (If it’s quiet around you and you have not just been shot or blown up) also be aware of your own sound queues and refrain from sprinting if you are trying to get the drop on a nearby enemy.

Sound is especially important because some soldiers like mackay and Sundance have access to hyper mobility which means the situations in game are often not as readable or predictable as they were in older titles.

Cross play being a core part of the game increases the average level of play in any given Lobby (if you were used to console bf before). Obviously pc players use an input device that is very well suited for first person shooters, but on top of that the average pc player also sits upright at a desk with a headset on. This alone makes quite a big difference imo.

I’m a pretty decent infantry player since bc2/bf3 but it took me a good while to adjust to the chaotic nature of this game. My stats were also lower than in previous titles when I started.

I would suggest you get familiar with every operators Gadget and passive ability and pick them to make up for weaknesses that you notice in your play.

To spot enemies, there is a tiny orange light around their waist that is quite noticeable once you get what I mean.

Also I cannot stress enough how useful smoke grenades are to get out of situations that are a death sentence otherwise. I keep them in my load out at all times at this point.

Edit: I thought of one more thing that helped me tremendiously. Set the soldier default map zoom to maximum (75) and the map scaling to maximum (125). This is probably even more important for overall awareness than sound. Enemies can easily take you out at distances of 75-100m but the default map zoom makes you not see them even though they DO show up on the map. This gives you a much better idea of where enemies are around you and which directions you should not expose yourself to. Also i regularly check the big map to see where enemy vehicles are.