My employer is accusing me of stealing $23k. How will I be charged for this?

Where in the world is this, and when?
Have you ever been charged with a crime before?
Have you been fired, or suspended pending investigation?
Has the actual charge been made?
Is it true and if so, have you paid it back?
What happens next depends entirely on what the employer wants to do, and the answers to the above questions, and more.

Police investigate , DA believes enough will issue warrant, or take grand jury and warrant issued
Time to get lawer

where in the world is this, and when?
Have you ever been charged with a crime before?
Have you been fired, or suspended pending investigation?
Has the actual charge been made?
Is it true and if so, have you paid it back?
What happens next depends entirely on what the employer wants to do, and the answers to the above questions, and more.
Its in Massachusetts. Not all of it is true. I do have a record but have never been found guilty. I'm just worried that police will come to my home and arrest me. How does it work? My employer submitted an 8 page document of all theft beginning of this week.

MA considers any theft value over $250 as grand larcery, with a possible 5 year jail term and $25,000 fine. Whether police arrest you or you are given a court date depends on the DA's office. They will know about prior arrests. I have no idea but it sounds like a toss up about bringing you to jail first. They may call you and tell you to come down to the police station for a talk and the prosecutor might be there, and they might arrest and charge you in the station.

You need a lawyer. If you can't afford one now, you can get one when charged, whether jailed or not. Since you are presumably going to be admitting to at least some of it, you should pay back all you can now so that you will be indigent (again, presumably?) and get a public defender. And because you should have course.