It is a good site for finding anything you need , video-wise. I have even used it for HW and class purposes. Still, adult content is rampant. Please be careful what you search and click on. It is completely safe in terms of malware, viruses and etc, though.
Overall youtube is a good site but the video loading times suck and there's numerous bugs that the dev team seems to be ignoring because they're too focused on making every video high def making youtube virtually inaccessible for users with low bandwidth (I have very good internet and yet some videos still load extremely slow)
But yeah besides that, youtube is good.
Good site to be entertained with many different categories. They're some videos that aren't suitable for children that why some videos are 18+ requires your account to be in that age group or you cannot view the video.
There's different movies/shows you can watch. Get caught up to the latest episodes. There's different trailers, Including game trailers, movie trailers etc.
Advertisements can get pretty annoying because they pop up during your video, Mostly during movies/shows.