We ask you to not modify the Naninovel folder, as it could break the plugin and make recovery and updating difficult. Instead, place the Resources under Assets for instance, and in case of tips, you need to place the Tips.txt file in Resources/Naninovel/Text/ folder.
As for the buttons, the following is outlined in the guide:
When there is at least one CG item added to any of the sources (no matter the unlocked state), CG GALLERY button will appear in the title menu allowing to access the CG Gallery browser.
When there is at least one tip record in the Tips.txt managed text document, "TIPS" button will appear in the main menu and control panels, leading to the tips browser.
Since not everyone will use these features, the buttons are deactivated by default.