A custodian pushes a large crate across the gym floor what forces are appied

The forces present in this context are two:

The pushing force by the person which is often called the "applied force". The friction force due to the surface of the ground interacting with the box.

Basically, these two are about the movement, that is, they are in the same dimension. However, there are other forces present, but they don't influence the movement, because they are vertical, and the movement is horizontal.

These forces are:

Weight due to the box mass and gravity. Normal force which is the reaction effect of the weight pushing down. The normal force is equal and opposite to the weight.

So, basically, in this contexts, we will only consider horizontal forces, the two first ones, because they intervene in the movement, and the vertical ones don't affect anything, because they are perpendicular to the movement.

When a custodian pushes a large crate across the gym floor, forces acting on the crate are the one applied by the custodian, frictional force acting in the opposite direction of motion acting between the surface of crate and floor and reaction force (normal force) acting in upward direction normal to the surface.