Well I kinda already have those instincts from playing Counter-Strike. But I don't get how to use all this equipment I see everyone using or how to get it. How do some people get helicopters for example etc?
different kill streaks they've chosen.
you can have any 3 you like (once you've unlocked them, you get an unlock every 10 or so levels, and you can pick what to unlock)
they can also come in care packages, or emergency airdrops.
(emergency Air drops are unlocked by default, if i remember)
you'll normally get UAV, counter UAV, predator missle or an airstrike in the care package, but ive also had an EMP (all enemy electronics stop working) and an AC130 (the airplane gun ship)
just incase: you get access to your chosen killstreak rewards once you've made the required number of kills without dying 3 for a UAV, 4 for care package etc.
once you've got the right kills, you'll still be able to use it after you've died, and if you were to say get a UAv, then a carepackage, die, and get another UAV.
you'd still have the previous 2 killstreaks, you just have to use the most recently gained one first.
that probably made no sense but i hope you get the idea