I need to resize the display on my 27" iMac

I actually was trying to make the screen image larger but wound up making the screen display itself larger, larger than the real estate it was showing on! Thankfully the reboot went to the default settings and I was able to also figure out my mistake.

Of course now I'm still stuck with too small type on the header of the computer, and the icons as well as the header on Safari. That is another issue to fiddle with today!

My font sizes WERE larger until I messed with things. I cannot recall how to resize them and anything I am finding at the moment is not helping in the right ways.. Using Command + increases the entire display size, which was what caused me trouble in the beginning. At least I know to use Command - to bring it back now!

Perhaps I'm missing the obvious but I can only change the dock size and the icons but the menu bar at the top doesn't change with any settings I've tried. I know it can be done because I did it before but that was so long ago I've forgotten the procedure and can't seem to locate it.

Also the type size on Safari is too small on both the tabs as well as the menu in Bookmarks, proportionate to the menu bar size. I somehow think the two are interconnected.

I managed to resolve the problem with a reboot. I thought I had tried it already, but regardless, it has been fixed~

Now the font sizes on the computer header AND the Safari header are a few sizes too small for my liking.