Dell latitude laptop?

i am computer illiterate...i bought a laptop on ebay and now have to figure out how to use it. i have cable internet. this new computer hooks up to a phone line. is there a way to program it to the cable system ? also is the slot on the side for a battery where i would not have to plug it in each time? i tried to pull up a manual on dell but web page wasn't available... so help please....