Question / Help New streamer with Lifecam HD 3000

[Zen1026]

I want to stream myself getting Legend in hearthstone every month and climbing to rank 1 in heroes of the storm. I bought a webcam and have a very impressive asus g20 2014 computer which seems to show a brilliant picture for me. I do not know how to get my webcam to take video and show me. I have added the webcam to obs and can get my game running fine. I hear myself and the sound is alright, although that is the next issue. How do I make the picture box of myself and shrink it to the corner of my stream? I just see a black square with no picture. All help is appreciated I am a newbie and want to learn!! Please help me stream