what's wrong with my 2003 acura Rsx base model ? there's a code showing P0780

First off do not drive the car with the trans leaking that bad. You will do damage to the transmission. The first step here is finding that leak. We won't be able to do that online. A hands on inspection is needed as it could be coming from any where. Here is a link to find a shop near you. You may want to get a tow or at least top up the fluid before driving it there. https://repairpal.com/repair-shops Alex