First, welcome.
Second, attachments are not acceptable,
so you'll need to place any document somewhere where you can then
include the URL for viewing by the list.
Now, to make tabs: you should notice upon opening LO, the list of
menu options at the top. Checking through these before entering data
should set your document as you would want it - tab can be set in this way;
then if you should wish a different tab setting in a specific
spot, just hightlight that spot whenever & choose the tab setting again.
Hoping this helps,