Chistina,
In order to answer your question fully, I would need a bit more information (like are you on Apple/Windows and what browser are you using).
As a generic answer:
- To speed up video in your browser you will have to install a browser plugin that allows you to speed up playback. No matter what browser you are using, check the plugin store.
- To speed up anything you downloaded (maybe to a podcast app) you need to review the app functionality of that app to see if it's possible.