Can anyone tell me how I can use/document articles and pictures in my videos? Like if I want to describe life in 2060, and find a picture of a futuristic city online, how should I document it?
Try Archive.org - they have a collection of public domain ‘futurist’ films and images made in the 1950s or so. If you can be certain that your source material is public domain, you can just use it.
Or just do a google search for ‘futuristic city’ and see if you can find one on a stock photo site such as shutterstock - then pay for it, and insert it into your video, ensuring that you comply with the terms and conditions of the content creator/vendor, and those of Youtube, which are here
Also remember YouTube “rules” are not the same as copyright laws. So even having public domain pictures in your videos can get them pulled if you’re not following YouTube’s rules.
And it can take sometime to get your videos put back if they are pulled erroneously. I know of one person who had his videos off line for a year before YouTube agreed they were pulled erroneously.
It’s not too big a deal if they are just videos but if you are making money off them, being gone a year is a big deal, plus it’s a strike against you.
You can use Creative Commons Search to find openly-licensed stock images on Flickr, Google Images, etc. It’s not public domain, but they generally have free-to-use licenses for non-commercial purposes.