The only confusing part is managing the load out and the briefcases and shit like that. I still don't get it.
Have a specific question? Your loadout is just what the soldier class is carrying. You get a primary and secondary weapon (usually a rifle and a sidearm), 2 additional slots for things like med packs and defib paddles (or rocket launcher/repair tool), and then a grenade slot. Plus you have a spec you can choose too. You have to unlock options for each class as well.
The briefcases are just bonuses that you get when you level up your soldier (point based) or level up a weapon (for every 100 kills). The briefcases will have point boosts or weapon unlocks (scopes, grips, etc.) or stuff to customize your emblem.
bf4stats.com shows some of the class unlocks better than Battlelog does.