It's no cakewalk (or cake-walk)
Meanings of "It's no cakewalk (or ..."
It's not easy, it's not something fun.
A cakewalk (or cake-walk) is a game similar to musical chairs. Participants walk on numbered squares while music plays. When the music stops, they stop moving and a number is drawn. Whoever is standing on that number wins a cake.
The game is often played at carnivals or as a fundraiser, where people pay a small amount to participate.