Direct debit payment plan approved. Is the initial payment i indicated to turbotax i could make required now, or would it just reduce fees and # of payments to b made?

The initial payment your proposed when you sent your payment plan agreement in will be taken as soon as the return is processed and approved if you put down banking or credit card information on the return. If you stated you would mail a payment in you need to do so ASAP. 

The IRS can void your payment plan agreement if they do not get the initial payment. The payment you agreed to make when you sent off the payment plan will be taken into consideration and will be applied to the balance outstanding.