1998 Saturn SC2 98 Saturn SC2 overheat

Engine Cooling problem
1998 Saturn SC2 4 cyl Manual

98 Saturn sc2 purchased for $800 on the condition I would have to fix the fuel pump, well it dident need a fuel pump, just some babying and some gas, after that the car started fine, I would let run for a few minutes and turn off, repeated this process a couple of times, took it for maybe a 5 minute drive, then I got in my driveway and a minute later I see steam coming from my engine on the right side of the hood, I open the hood and see a bunch of engine coolant where I believe to be coming from the cap, however I have learned it could be a splice or pinhole in the hose, or a thermostat, or even a crack in the resevior. What do you the actual problem is or the part that needs to be replaced. Thanks.