You have some choices while building up your store of AutoTexts/Building Blocks. The first question is where are your current Quick Parts being stored. If you have already made some, you probably see the Building Blocks Organizer around the same spot on the ribbon where you made the individual items. You probably either saved them in your Normal template (Normal.dotm) or the Building Blocks template.

If you're on a recent version of Office on Windows, your Normal.dotm is probably located at:
"C:\Users\[your user name]\AppData\Roaming\Microsoft\Templates\Normal.dotm"

Your Building Blocks .dotx is probably somewhere like:

"C:\Users\[your user name]\AppData\Roaming\Microsoft\Document Building Blocks\1033\16\Building Blocks.dotx"

You can also find an old thread here I initiated, in which Mr. Kenyon not only gave me great advice about building a Global Template.dotm which could be shared, but also about Graham Mayor's add-in which allowed for import of a whole string of client addresses I wanted to place in AutoText (works a treat!).