If you get stuck with your code and want to use a library that works by defining the menu in data tables, you should look at this one that is designed specifically for 1-2 line LCD modules:
Library MajicDesigns/MD_Menu: Menu system for displays with up to 2 lines (github.com) or install MD_Menu from the IDE library manager. Look for library documentation in the docs folder.
Blog post describing the library A Menu System for LCD Modules – Arduino++ (wordpress.com)