`:set clipboard=unnamedplus` let's you use the Xwindow clipboard for `p` to paste.

I also believe Neovim (and possibly normal vim, I'm not sure), automatically does `:set paste` and `:set nopaste` when you use the terminal paste.

Just to add, I highly recommend people to look at `:help 'clipboard`. There are several options available, and one or another might be better depending on what you're expecting, and on which platform you're on (e.g., there are notes about using the clipboard on X vs. Windows).