First off a cavate, all councils differ !
My local council have to date been very good.
I have received the same incentive payment as you, twice now and used it to update the property.
The council should have a department who mange this incentive and help with the tenant. The AST provided helped you receive the incentive. This is an income and taxable.
Now you need both rent and deposit
The council may also pay the deposit but here be careful as if you register it some deposit agencies will only return the payment to the tenant, not the third party. Which means you become liable. Either sort this out in writing with the council first or use a different method or registering the deposit.
If you accept rent direct from the council, write to them saying you will only accept this for rent and not be liable for any repayment of any kind where the tenant’s financial status changes. They will not like this and beware of signing anything to the contrary. So you may be better getting it direct from the tenant.
The tenant probably will not pass a credit check but do it anyway to see if any surprises pop up.
As a first time landlord you really need help and whilst a forum is helpful, as Colin has said join the RNLA. They have a host of forms and helpline. It will be money well spent and can be offset against your rental income, yes you will have to declare and pay tax, you cannot just allow your personal tax allowance to cover this.
If it’s your property you have rented you must inform the mortgage company.
There is a lot of procedure to follow to protect yourself - see the RNLA website, otherwise you will be on here in a few months asking for help re non payment and legal action
get yourself organised, its not all about getting a rental income
one last ting , get a tenant guarantor