Also don't get hung up on BF2 PR being a 'milsim' - It's not, it's an arcade game made to look and play 'realistically' in terms of simulating a battlefield.
It's all the better for it, you can hop in and out of games fairly easily, it feels natural to run around (not clunky, etc).
As previous people have mentioned, get familiar with deviation. It's there to simulate tiredness and adrenaline affecting the soldiers' aim - Frustrating at first but it's the only real option the developers had within the limitation of the BF2 engine, and you'll get used to it.
It takes 3 shots to kill an infantryman, or 1 head shot.
You spawn in the game on player-made spawns called 'FOBs' - these are made by the squads you see and have limitations on where they can be placed. The enemy can destroy them.
Cars and tanks etc spawn only at main. It's bad manners and frowned upon to take them just to get somewhere by yourself (they are limited).
The game is made to encourage people to play in squads - it is possible to lonewolf (avoiding the admins as well as the enemy) but to do so really denies you the fun part of PR.
Join a squad and tell everyone you're new and they'll explain the game better. Have fun!
THIS IS THE CURRENT 'MUMBLE' VOIP PROGRAMME THAT ALMOST EVERYBODY USES:
https://www.realitymod.com/forum/f10-pr ... ality.html
It lets you speak to everyone else in the game so you can hail passing tanks, soldiers, etc.
You'll need to set up the 'Overlay' so you can see other people's names light up when they talk to you (if you want that, we all use it I think though).
You'll also need to bind the Transmit function to a key on your mouse or keyboard. Be careful not to use the existing BF2 VOIP key of everyone hears you twice.