Hy, my friend.
The Vim unnamed register is used to store any text yanked or deleted using the normal mode mappings like "d", "c", "s" or "x". If you need to keep the text you yanked to use it several times, you need to place it in a "named" register. For example, selecting a word, or sequence of words, and type, in normal mode:
"ya
This will place the selection in the register 'a'. When you need to paste the text in this register you will use, also in normal mode:
"ap
See the help at 'registers'
:h registers
Also see "Copying and moving text":
:h copy-move
Regards,