How do I get to Task manager on a LG G4note?

[AC Question]

I have been having problems trying to play games on my Phone. I can play for a short while, but then the app will stop and my Phone will return to home screen. I was finally prompted to go to Task manager on my Phone (an LG G4note) and stop/turn off app. However, I am unable to locate exactly where the "Task manager" may be...can someone please give me a clue I'll take a hint as to where to go and what to do? THANK YOU!