Coolant leak

There is a coolant leak and the outside of the engine has coolant in several different locations and so it’s hard to find any specific location that it’s coming from. I know the leak is high up on the engine and because I can see that there is a small amounts up high and increasingly more down low. The coolant reservoir was bubbling and I could hear a sizzling/hissing noise next to where you put oil in the engine. Also small amount of smoke coming from the same area. Any chance You have a good idea of where my problem is or where I should be looking first. I sat there with a flash light for an hour with no luck. Thank you for your help.
-James