Before you start making the level, you need to create some pickups for the player to collect, since those will be part of the level as well. The assets/sprites folder contains sprite sheets for two types of collectibles: cherries and gems.
Rather than make separate scenes for each type of item, you can use a single scene and merely swap out the sprite sheet texture. Both objects will have the same behavior: animating in place and disappearing (that is, being collected) when contacted by the player. You can also add a Tween animation for the pickup (see Chapter 1, Introduction, for an example).