Identify the prepositional phrase in the following sentence:

The first game of the season will begin soon.

i think the answer is of

I would say "of the season' because "of" is the preposition and "season" is the object of the preposition.

For every prepositional phrase, you start with the preposition & end with the object of preposition.

Since game must be the noun, season cannot be, so it is the OP.