Each loan has a loan schedule which tracks when your minimum monthly repayments are due.
Regardless of whether you have chosen to pay weekly, fortnightly or monthly, the due date is always a month after the loan is established (we refer to this as the 'anniversary date').
If you chose to pay weekly, your repayments will start a week after the loan is set up to ensure that you have made 4 payments to the loan by the anniversary date.
Your Minimum Monthly Payment is $400 and you chose to pay weekly.
You would pay 4 installments of $100 per week starting 1 week after the loan is established.