Hi Kimmy,
It can be your server PHP version issue.
In this issue, you could follow the steps below.
1. Please make sure you have the latest version of WordPress and update your hosting server PHP version to minimum 7 or newer. ***recommended***
2. Clean your full database “OR” reinstall a new WordPress with a new database
3. Then install the theme (follow the steps from the provided documentation)
4. Then install all of the required plugins (follow the steps from the provided documentation)
5. Then active all of the installed plugins (follow the steps from the provided documentation)
6. Then import all of the demo data (wait until all of the demo data are imported completely)
About the menu, it all about the megamenu issue. If you have installed the megamenu plugin, then select the megamenu on the Appearance -> Menu
http://prntscr.com/mkuftr
If you don’t need megamenu then please deactivate the megamenu plugin to fix the issue.
Best Regards,
ThemeLooks Support Team