Well it's not like every PC game has the same controls, unless you don't know how to type we all have to learn the controls for games. You'll get used to it. If you have a mouse with a middle button and maybe side buttons, that can really come in handy.
You weren't very good with the controller the first time you picked it up either--at least I would imagine.
One thing that can help is going in and reassigning the keybinds. Map your most used abilities to the easily accessible/comfortable keys. --- "Hurry now! My muse is a fickle b****, with a very short attention span!" Sander Cohen
Just practice. Also I always move my crouch button to left alt. Its easy to access with your thumb.
As for mouse aiming, be sure you adjust your sensitivity to find something that fits well with you. --- "Jack Tretton, chief executive of Sony Computer Entertainment America, says he is pleased to see so many unsold PS3s sitting on shelves." -IGN
There's no real good way to learn other than practice, I guess. :)
Focus on learning what keys do what and moving your fingers to them and after a while you'll get the hang of it.
It's actually not too bad.
W,A,S,D - Movement Space - Jump Ctrl - Crouch Z - Prone Q - Spot enemies/give commands F - Melee G - Grenade J,K,L - Chat to all, team, or squad (Can't remember which order) --- I did absolutely nothing, and it was everything I thought it could be.
I would recommend joining some less populated servers and slowly easing and adjusting to your keys. Laptops have small keys, at least many that I've used compared to my fingers have, so it takes time to get used to them but you will. Just keep at it. --- "If I was a dev, I would be proud to point out in a game I made that the best weapon to kill a hoard of children was the flamethrower." - Gigabomber