Optimizer Theme Main Menu

I am creating a website for my small business https://www.southerlyselfies.com (new to WordPress so I am learning as I go). I have installed the Optimizer theme and I am having trouble with the menu in the header of my webpage.

A few days ago when I was building the site, I had a general menu in the header of my site that listed all of the pages for viewers to see and click on. I made some updates to the site and now my menu has switched to what I understand to be a “hamburger” menu in the header. I would prefer to have the general menu with the page names listed out. However, I am unable to see any menu when viewing in my browser and on larger iPhones (6S, 6S+). I have gone through all of my settings multiple times and cannot figure out what happened! Any advice?

Thanks for your help in advance!