Start by creating two folders with your operating system, NOT kicad.
Name these eg. My Kicad Symbols and My Kicad Footprints or whatever you prefer.
Next, open Kicad / Schematic Editor / Create, Delete & Edit Symbols
Up comes Symbol Editor.
Click File / New / Choose “Global” and OK.
Up comes a “New Library” screen…
Next, give your library a name.
Click on Other locations to find the symbol folder you created.
Highlight that folder then save.
Repeat this for as many libraries as you require.
Note: think about your naming of libraries and how many and what goes in them.
I have 15 different symbol libraries.
@BlackCoffee shows you his examples.
You can add more libraries as you wish in the future.
Next, you have to show the paths of these new libraries you created to kicad.
Go to Preferences / Manage Symbol libraries / click Global then the Folder icon…
This will bring up a “Select Library” page and again use “Other Locations” to find and highlight the new libraries you wish to add.
HINT The Nickname determines the position of the library in the list of libraries. If you wish to have your libraries at the top of the list prefix the nickname with a number lower than 4 eg. 1connectors.
This procedure cannot be done in bulk. You need to add the libraries individually clicking OK each time.
Now you should have a list of new empty libraries probably at the top of kicad list.
Open up your Symbol Editor again, scroll through your existing personal libraries, find each of your personal symbols and, one at a time, right click it, select “save as” then in the new “save symbol as” window, scroll through the library list to find the new, correct library in which you want the symbol placed, change the name of the symbol only if you wish then click save.
Repeat as required for all your personal library symbols.
Not lame, and if there is something from the above you do not understand, please ask.
One more thing: footprints work exactly the same way, just substitute the word symbol for footprint in the above and place your new footprint libraries in the footprint folder you created.