Hi Sillywan,
I’m not a sir. No royalty has yet seen fit to grant me a knighthood, but I live in hope.
Most members of this forum have been using CAD programmes forever and then some, and sometimes tend to overlook the very basics, thereby confusing the absolute newbees. Never be afraid to ask for clarification on a subject.
You are using 5.1.7 I’d suggest, before anything else, you upgrade to the current 5.1.9
You will find it here:
https://kicad.org/
Rene_Poschl (this fellow nearly deserves a knighthood for his contributions to Kicad)
posted some links to excellent tutorials. There are many more.
This one should help you setting up your schematic libraries:
[Creating a new symbol library and a new symbol in KiCad 5]
Hint: make your library “global” so you can easily access your 4007 in your next project 
Start your new library name with “1a” so it is easy to find at the top of the library list.
You will find lots more instructions in the FAQ link at the top of this forum.