New guy from SC with some questions

Hello everyone. im from columbia sc and just bought a 1999 toyota camry le automatic four cylinder, and its black for 600 dollars. everything works inside and it has a sunroof and cold air. the bad is it needs a water pump because its running hot and the fans are not working, they only come on if the aircondition is on, but they still dont wrk like they should. so im not driving it until that gets fixed. I also put in a new thermostat, but that wasnt the cause of the overheating. I visually see water coming from the weep hole on the pump. is it diffficult to do the pump job yourself? also the check engine light is on and says misfire on 2 cylinders, egr valve, and somthing about the air flow, which will explain why the car runs rough. also needs a valve cover gasket and maybe new spark plugs. the car has 237,000k miles.