I am a c# programmer new to SharePoint. The customer has a SP 2016 standard farm. I want to add a custom c# web-page to allow a user (who has the rights) to search using external API for an item.
I then want to programmatically add a web-page to SharePoint with which users (with lower rights) can view. Ideally the web-page should be located where the user wants (using some normal hierarchy in SharePoint).
What web technologies in SharePoint is appropriate for this version and purpose that I should be studying to achieve the above?