As far as my understanding is correct, p always has the same effect (pasting the content of a buffer, by default the " buffer).
In Vim they say "putting", not "pasting". And what is more important, that particular "thing" is called "a register", so to find a relevant help topic you should type: :h registers, not :h buffers (which will lead you to a totally ...
If you can't figure out how to get +clipboard to work, which I couldn't for some reason, then you can do this.
Assuming you only want to copy a section of the file, I do shift+v to go into visual mode and only highlight the lines I want to copy. Then I do this.
# Linux Wayland
# Linux Xorg
:'<,'>w !xclip -selection clipboard