Let's go to school together. What does "arrive" mean?

First of all, "Let's go to school" translates as: Let's go to school together!

The usage of to is: as a preposition, indicating the direction; To (a certain direction or place); In the direction of; Arrive at (a place); Reach (a certain state); Before the beginning of; Pay, pay, pay again; Of, relating to, or for; Give directions; Than; Equal to, every, one; Pay tribute; Accompany; In order to give, in order to provide; Suitability, conformity and cause; In the opinion of; As an adverb, it means going and approaching, and to can also be followed by the verb prototype to form an infinitive. When learning English, we will encounter many prepositions, and to is one of them. It has different meanings in different contexts.

The to in "Let's go to school together" stands for the direction; To (a certain direction or place).