So this will be the third time i had to fill up my antifreeze reservoir i also noticed that there is some antifreeze on the bottom of the car, laying below the radiator(just on the bottom shield thing). What are common leaks and would this leak cause a loss in horsepower?

 

Radiator or hose. You need to put the car on ramps or jack stands and start it and look for leaks.

 

ok, will this cause a loss in horsepower?

 

Shouldn't. What year is the car? If it's a water cooled turbo and it's not getting coolant and burned up I guess it can. Coolant is used to cool the motor (block) and heat the interior. Some times cool the turbo.