To answer THAT question, YOU have to decide what you don't want your users  to see.  But for hints, research the topic "Securing a Database" on this forum.  We have had MANY articles.  Lots - but not all - are from our member Isladogs either as original articles or in response to this kind of question.  It all starts with a "pure" developer's copy that you NEVER release to the public, but instead make a production copy that gets the special treatment of turning off or hiding features.  There are ways to hide the ribbon, the object list (a.k.a. navigation pane), and certain other features.  The idea is that if you are going to start hiding things, you don't want your users to be able to open things that are unguarded - like tables and queries - where they could change content without going through a checklist of "do" and "don't do" rules.  The "Securing" articles will explain it all.