Formless Nurturing is a common Sorcery card from The List (PLST), collector number FRF-129. Current market price: $0.26, TCGplayer market prices via Scryfall.
Manifest the top card of your library, then put a +1/+1 counter on it. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)