Problem with Page/Post header

I am trying to set up a new site but I had a power outage and something caused me to reboot while I was playing around with different ideas and I ended up with the menus strung out in the header and I have no way to eliminate what now is garbage in the header. I am using the Storefront theme with Woocommerce. How do I clear up this mess? Please be detailed since this is my first experience with Wordpress. Thanks for your help.
Richard Martin