[e2e4]

I am about trying to understand English grammar as well and would say my opinion.

You can enter into the house and put books onto the desk.
You can't enter onto the house and put books into the desk.

There was a comp on his desk.
We are going into the museum.
I bit into an apple when saw a snake at the front of me.

Could be a lot of chairs or rooms in the house, or inside the house but usually you will not say could be a lot of rooms into the house.
Into is used if are you entering into something but not if something is already inside something else.
Into is used if are you pushing something into something else but at the moment of speaking.
Also you can't say we are going to go into Italy next week.
You can say We are going to go to Italy next week.

etc..
Comments welcome.