Apologies - I was on a call when you put your request through and a colleague has picked it up.
They will call soon.
in the meantime, to put formal arrangements in place for your son, you will have to start by attending family mediation - see here for a link to find your local mediator:
Assessments are usually around £30-£40, and the mediator will advise as to how many sessions might be required. Mediation is a collaborative approach and allows you to talk through issues and concerns in a safe and protective environment.
Following that, if the mediation does not succeed in a successful agreement, you can apply to the family court for a child arrangements order (see below description), setting out the living arrangements and contact arrangements that you would like to see.
You would apply on a c100 form, here:
You send 3 copies of this form to the local family court centre.
Alternatively, you can apply online:
Here you ask the court to set the ground rules for contact, such as time, frequency and how and where it should take place, whether it should be supervised or not, that sort of thing.
There will be a court hearing after you apply and a family court adviser will be there in attendance too (from CAFCASS).
The application costs £215.00, and you can represent yourself so you don't need to engage a lawyer.
I hope that this assists you.