If you’re creating videos on YouTube, there is free audio resources in their Creator Studio. Some require copyright text in your description, most don’t. It’s not great audio, but it’s free.
Copyright laws vary from one country to another, and there is international copyright laws. Basic terms… unless you created the image, video, sounds yourself, you don’t have copyright. Copyright is defended in court.
And idea for images could be your own. Take your favorite mug/glass fill it apple juice/beer/wine, position it in the sunlight on a table with fruit behind it. Take a photo. Play with that photo in a photo editor for various looks. Take video/pictures of a train passing by. Find a local car show, attend it. People love it when you take pictures of their cars. You don’t need expensive cameras for this. If anything find one of your friends with the latest smartphone and ask them to take pictures for you and send them to you. This was shot from an Samsung S6 smartphone. Will not win me any awards, lol, but it’s mine to do with what I want. The same could be done with Anime figurines that you own. Look at ACBA to see what I’m talking about.
Cost if items: $1