"Into" is a preposition that indicates movement or direction from the outside to the inside of something.
"In to" is usually incorrect unless it is used to indicate two separate words, like "I walked in to the room" (meaning you walked and then you went into the room).
Here are some examples of how to use "into":
* She walked into the store.
* He threw the ball into the basket.
* The cat jumped into the box.
* I poured the milk into the glass.
It's important to remember that "into" is a single word, not two separate words. So, if you're ever unsure about whether to use "into" or "in to," just think about whether the sentence is indicating movement from the outside to the inside of something. If it is, then use "into."