To get into something is to become interested and involved with it.
I got into computers when I was about ten years old.

And you say that you ‘get into’ bed.

‘Get into’ is used to say become involved without intending to.
He got into trouble.

It also means to start behaving in a particular way.
She's got into the habit of chewing her hair.

And it means to be accepted as a member of an organisation
I got into a good university