I’ve had this problem with my pc keyboard. Ive spilled soda and other liquids onto it countless times. You’d have to manually take off every key and clean it off with electronic safe wipes, then place every key back on. Since its only water, wait a few more days and let the laptop dry out completely and try by it again. For some reason keyboards tend not to work when they are wet, but are fine as soon as they are dry with no hurt. But having a 2002 laptop it is about time to have it replaced. Computers and laptops only last around 5 or 6 years before they start to slow down and malfunction from age.

just google ur laptop model – keypad they are only around 60 dollars and can be done by u
use utube –How to replace a laptop keypad –takes 10 minutes of ur time