Search your library for a Plains, Island, Swamp, Mountain, or Forest card and put that card onto the battlefield. Then shuffle.
Spoils of Victory allows you to search your library for any card with the land type Plains, Island, Swamp, Mountain, or Forest, not just a card with one of those names.
Because the “search” requires you to find a card with certain characteristics, you don’t have to find the card if you don’t want to.