You will almost certainly need to submit a planning application to your local authority for a change in use for the premises to run a commercial (fee-paying? revenue-generating?) enterprise from a property that presumably had planning permission granted and was built as residential only.
As you will be running a commercial enterprise in the property, the local authority will want to levy commercial rates on it and you will be subject to inspections by the fire officer and to health and safety audits, to name just three agencies you will need to interface with.
If you have a mortgage and are claiming TRS, your lender will also have an interest in the change in use as the property is no longer exclusively residential, which presumably was the basis for gaining mortgage approval and being granted TRS, if applicable.
You will absolutely not be covered on your basic house insurance to run the enterprise you describe in your home and to do so would leave you, your family and potential clients seriously exposed. Unfortunately, I believe that insurance is the least and possibly the last of the difficulties facing you.