Update Custom Shopify Menu and add/remove menu items

We are working on the [login to view URL] website. The site is built on the Shopify platform. We are looking for a resource that is very knowledgable about the Shopify platform, add-in, customizations etc... Requirements: 1. We have several individual products under the shop menu that we would like to group into a special collection. 2. We need to add a new menu item (Shop>New Menu Item) nested under the Shop menu in the top navigation. Note: there has been some add-in and or theme customization done and the normal path Admin>Online Store>Navigation configuration settings don't seem to be working. So, we are thinking we have an app/add-in or theme customization that is driving the rendering of the top/main menu. We are looking for someone with enough experience to quickly understand this implementation and then be able to help our non-technical business user to update and maintain the online store while it reminds on the Shopify platform. 2. We would like to removed the custom orders menu item. As stated before, depending on our experience we are interested in an on-going relationship. By friday deadline