channel settings

Hello guys. I was thinking to create a kids entertainment channel (you know, those annoying channel that play games on tablet and are everywhere) just to see how well i can manage a Youtube channel and see how far i could get with it, but i really need your advice. And i need it like step by...

Some of my videos require me to approve comments on the first before they are shown publically, other videos of mine just allow the comments to be posted on them straight away. :P Is there a way I can change all my videos at once to Allow comments without approval instead of me having to go to...

I looked at my channel as a new visitor would see it and noticed that at the bottom, my 3 older videos are popping up over my newest ones (and my old ones are bad because I wasn't using a mic). Any idea how I can change this and make the 3 videos that show up to be my most recent videos or 3...