The fastest way to find a vacuum leak is with a can of "starter fluid" available from any parts place. Start up your engine and spray any suspected areas. The idea is once the mist gets sucked into the running engine through the vacuum leak, there will be an increase in RPMs. When you hear the engine "rev up", you know you have the right area. Now just turn the engine off and look in the area last sprayed before the RPM increase.
You do not want to go spraying everything at the same time. Just spray an area, and move on. The RPM increase will be immediate. After you found the area, I would stop the engine and look for any vacuum lines that are disconnected. If you are new to mechanics, it is far better to check an engine compartment with the engine off then with the fan blade revolving...