Request

Hello, I am very much out of the loop of new tech and could really use some advice.

I want to put together a system that is good for 

• Gaming (decent enough quality to where I don't have to worry about lagging issues)
• Multi tasking - using Excel while watching Netflix/streaming for eg
• Video editing using Adobe Premier

I have monitors, keyboard, and a mouse but no other components. I do not need a full size tower. Please include windows in your build.

Thank you all in advance.