"into" is usually related to physical entities or actions. He went into the store. She walked into the wall. The cat went into the house. "in" is general and can be used abstractly or to express transfer (prescriptive). She put the cake in the bag. They walked the dog in the house. or an abstract idea, In the morning, I like to have coffee. In the afternoon, I drink tea. In his lectures, he talks about the news.

In simple terms, "into" is a preposition of movement and implies an action. For example, "He put the book into the bag". "In" on the other hand identifies a preposition of place, without movement. The car is in the garage.