I know that 24fps is the standard rate for movies.

Presumably, if I want to shoot for a movie I should shoot at 24fps, however if I want to add slow motion effects in the movie I know that I need to record at higher framerates(50-60 fps.) When I convert that in to 24fps I get slow motion but then I don't have 24 fps for the rest of the clip since I only need slow motion for a few seconds in the middle of the clip.

I don't know whether to record videos at 24fps for a movie look or at 60fps for the slow motion look, or something else entirely. I have to shoot one continuous shot so that I can have both normal and slow motion at different points without cutting. What is the best way to accomplish this?