Virtually all emulators have options that allow you to remap controls. The vast majority are actually mapped to keyboard functions by default, requiring you to redefine the controls if you want to use a joystick or gamepad.
Look for 'Input' or 'Controller' options.
PCSX2 is unlikely to run (well/properly/at all) on your Laptop regardless of the OS installed. Emulation of recent systems like the PS2 requires a balls out PC to have anything close to functionality (Top end processor, top end GPU, 2Gb+ Ram). Even a dedicated gaming spec laptop like an Alienware will probably struggle with it. The emulation is still far from complete and many titles won't run properly on any system.You should be ok to run PS1, N64, and just about every older computer/console emulator though.
The best ones are generally available for download from this site. Once you have chosen which systems you want to emulate and installed the emulators, if you are still struggling to get them set up or remap the controls then post again and people can assist you with set up for the specific emulators you are trying to run, since each one generally has different options, requirements and functions.
For Project64 for example, go to 'options' > 'controller plugins' and you can remap each control there, although to be honest with the number of controls on an N64 pad and considering the majority of games on the system used lots of them, playing them with a keyboard will be pretty pointless and unsatisfying.
I would recommend sticking with older systems like the Megadrive, Snes, Master System and NES for keyboard play.
Hope that helps.