S3 Graphics Ltd. VT8375

[gold_finger]

Plugged your graphics card into Linux Beginner Search Engine and saw that it does appear that your graphics card has issues on several Ubuntu-based distros.  Didn't find any good solutions other than one poster who said it worked fine on LXLE, so you may want to give that one a try.  (Another possible alternative would be AntiX.)

As far as youtube goes, you're going to have problems running flash videos on that machine because Adobe discontinued flash support for older CPUs like the one on your machine.  Two ways around that are either:

1. Install an older version of flash-plugin that will work on that CPU, but has greater risk of security vulnerabilities.
   
2. Set browser to use HTML5 video on Youtube instead of flash.  (Use search engine to find out how.  I don't know exact steps.)
   

Either way, streaming video performance is not going to be great on that hardware -- particularly if you try viewing videos in full screen mode.