Newbie...sorry if this else where but ...

[KatMan1963]

Hey, I am brand new to this and I would like to know how I can watch a youtube video and record on OBS to record a reaction video. I have read the online manual and there is nothing there. I cannot get my camera to show me in the preview either I have a double screen view (preview on top) and recorded on bottom. Help!

 

[FerretBomb]

To get out of the 'double screen view' (studio mode), click the 'Studio Mode' button in the bottom-right next to the 'start recording' button.

Here's the quick-start guide:

OBS Studio Quickstart

OBS Studio - Free and open source software for live streaming and screen recording - obsproject/obs-studio

obsproject.com

I'd also recommend watching the Nerd or Die tutorial video series:

OBS Studio Tutorial Series Introduction | Tutorial 1/13

Welcome to our OBS Studio tutorial series! In this series we're going to cover everything that you'll need to know to make your stream look great.Next Video...

www.youtube.com

 

[lofihap]

Best way to record a YouTube video or anything from a browser source - is to add it to the scene as a browser source.
You could also do a full monitor display capture.