When I open Firefox and try to search or open anything I am redirected to a page that is not what I want. How do I stop this?

Can you provide an example? Where do you end up? You may have ad/mal-ware. Further information can be found in this article; https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware?cache=no Run most or all of the listed malware scanners. Each works differently. If one program misses something, another may pick it up.