"We are starting to study Japanese at school."
Translation:Empezamos a estudiar japonés en la escuela.
It is very common to see a preposition after a verb.
Here are some examples in English: "to looking for", "to meet at", "to come with", "to look up to", "to belong to", etc.
In spanish, there are also prepositional phrases: "terminar de", "empezar a", etc.
Some of the verb-preposition combinations make sense. For example, saying "moving toward", "moving away", and "moving through" all signify a specific direction of movement.
However, other verb-preposition combinations don't necessarily make logical sense. For these, you just have to use memorization.
"To approve of" is an example of a verb-preposition combination that doesn't make logical sense. Why would you say "approve of", instead of "approve in"?
Clearly, when an English verb is followed by a preposition, a Spanish verb may be followed by a different preposition. Moreover, when an English very is followed by a preposition, the Spanish verb may not have a preposition. The converse, in general, is also true (i.e., when a Spanish verb is followed by a preposition, the corresponding English verb may not be followed by a preposition).
Because of your familiarity with English, it might be difficult to accept other kinds of prepositional verbs. My advice, when learning Spanish prepositional verbs, is to not think about them too much. Just keep you mind open, and accept that a Spanish phrase is said how it is. As you gain more familiarity with Spanish, these things will become so ingrained in your mind that you will wonder how you were ever confused by them.
Adding to the discussion for the particular example you are concerned with:
"Empezamos a" is a verb, followed by a preposition. This verb-preposition combination is very easy to translate, since we have to exact same verb-preposition combination in English ("to start to"). In fact, the above example uses this, when saying "starting to".
"To start" is translated as "empezar", and "a" is translated as "to".
As noted in my more comprehensive discussion post, not all verb-preposition combinations translate this easily. Just keep this in mind.
I wish you the best in your future studies.