How to get of default footer (buy now), and default sidebar information and link

As said in the title, im having trouble finding a way to get rid of the defaults that have been put on your theme. At the bottom of the page their is “Experience something completely different. The most powerful theme ever.” Wit a BUY TODAY! button. I would like to get rid of these, and know how to get the BUY TODAY! button to instead add something else that links somewhere, or how to altogether delete it.
Also i can not figure out how to get rid of the options under the search bar such as recent posts, recent comments, archives, and so on and ect. Can you please make a video on how to get rid of this and turn the whole theme into woo commerce setting, as my site will only be a fashion store?
Thank you very much for your help. Pictures attached below.