Khamsho,
Everything you need to know about ATP is readily available on their site, I’ve linked below a direct link to the information you need to know:
You will need 1,500 hours of flight time to be an applicant for the Airline Transport Pilot (ATP) certificate, which is broken down into various paragraphs and sections under 14 CFR Part 61.153-.159. To build flight time, most pilots will instruct; however, some take various routes of aerial photography, banner towing, skydiving, etc. along with charter/corporate routes.
Brady