Windows 10 - Photo Woes

I just updated my computer to Windows 10 this past week and it really went without a hitch except . . .the way it organizes and opens up photos is totally messing with my brain.  I can't find them on my computer yet I can see them and open them within windows and when I want to open older photos, it wants to open them in some other photo organizer.  So, I'm trying to figure that out and then I can post more photos :-)