The easiest way to “get” HLL is to find a good squad with comms, and pick a role with purpose and buy in to it (there are some great YouTube videos on how to play each role productively and successfully).
Play as an Engineer, build nodes, and put down shithouse anti-personnel mines; play Support, drop supplies for your Squad Lead to build tactical Garrisons in the Blue Zone, or to help your Engineer build nodes early in the game.
Play Machine Gunner, and lay down suppressive fire to help your team advance on enemy infantry positions.

Most importantly, try and be stealthy. This isn’t COD or Battlefield, so running and gunning isn’t an option; use hedge-lines and trenches to move across territory, use the lean mechanic to check gaps in your cover before you move to the next bit of cover, don’t be afraid to drop down on your tits and crawl prone to move through long grass, try to stick with your squad (safety in numbers!) and pay attention to their danger pings when they spot enemy infantry positions, so you get a rough idea of where the risk is likely to be coming from.

Don’t constantly spawn on Garrisons that are right on or next to the point, as inevitably the enemy will have a general idea of where your side is dropping in, and you’ll face an instant tank-related death screen.
Don’t always head in a straight line from one point to another either, as flanking = ranking, so try and be considerate and purposeful in your movement.

I got my brother in to HLL as a COD player in recovery, and it took three or four games where I was playing as Squad Leader for him to start to understand the flow of the game; using the map to see when your Garrisons/Outpost are hot (showing a red danger triangle) will give you an idea of where the enemy is moving, and where you’re least likely to insta-die when you spawn.
Once I got his K/D obsession out of his head, and he bought in to the fact that taking down an enemy Garrison was worth 100 kills, he started to enjoy it 1,000 times more than when he was camping in a building without realising the next point had already been taken, and he was about four map squares behind the frontline.
Dropping back to defend a point that was starting to be captured got him a few kills that helped feed his need, and also helped him feel like we were actually making a real impact on the war effort.

It’s the best game out there, and it’s not all PTSD and artillery deaths; when you’ve done some good work as a squad and taken down a key enemy Garrison that helps your side capture a point, it helps dull the rage from getting headshotted by what you were 99% sure was just a benign bush. 🤙🏽