I have 1 website which is full of Videos and PDFs, which makes it more users interactive, but it is somewhat not good for SEO Bots, how can i make it Usable along with the SEO optimization?
If the site is not accessible to bots, then it’s also not accessible to real human visitors using assistive technology, such as screen readers, or deaf visitors unable to hear the video soundtrack, etc. You should provide alternative content for these visitors, which will also be accessible to bots. e.g. a transcript of a video. http://webaim.org/techniques/captions/ You should also ensure PDFs are accessible: http://webaim.org/techniques/acrobat/
Having PDFs is not necessarily a problem for SEO, because search bots have been able to read PDFs for years, which is how you’ll see PDF files listed in the search results. What can be a problem, for both SEO and usability, is when you don’t provide any links from the PDF back to the main site (and preferably relevant deep links rather than just to the home page), because then search bots reach a dead end, and any visitors who arrive from a direct link, either from the search results or another site, have no way of reaching the rest of your site.