I really don't recommend overclocking a laptop either.
Compared to desktops, laptops are far more constricted with ventilation, so it's not as good of an idea to mess around with overclocking on laptops lol.
To overclock you have to enter your BIOS settings, usually achieved by pressing one of F1, F10, F11, Del, or some other button/combination of buttons. Each manufacturer/BIOS uses their own key combination, but it's usually listed right when you turn your computer on as 'Press XX to enter your BIOS settings' or something.
Your BIOS settings may have the CPU speed locked though. For example, I think all HP computers, even desktops, do not allow overclocking through their BIOS. To fix that I think you'd have to flash/overwrite your BIOS and install something custom, but I don't recommend that at all.
On a desktop you would be able to easily replace the motherboard easily, but this is probably not possible for virtually all people with a laptop lol.
Anyway back to main point, I don't recommend trying to overclock your laptop either. Just be happy your computer is working for now and wait for updates for PCSX2 to make it even faster
You should be able to play a few good games at full speed or good speeds. I'm sure FF X or Kingdom Hearts would work with a lower speed than full, but playable.