The Theme Doesnt Seem to be Adjusting to Mobile and Computer View

Hello, I am using the Thalia theme for my web store. I would love some assistance in getting the theme to properly adjust to different views. As of right now, the theme is the same on every view so things look a little strange especially on mobile view.
Thanks in advance

@Mackenzieelaine

Please provide us with a link to your store so we can investigate further.

Hello Here is my link! I did get the videobox working however now my issue is getting a customizable About Us page. There is no template available to do this even after following the instructions. Here is my link https://dbh6kw5zk024d6xm-48721133721.shopifypreview.com. If you want to email me directly please let me know.