Gstr 3b - annual supply less than 20 lac (voluntary reg)

Dear Friends,

Since i am expecting annual turnover will remain less than 20 lacs during this financial year, So have have taken voluntary registration under GST.

In the month of July, i have made sale of around 2.5 Lac and did not charged any GST on above sale.

Now my query is .. 

1 . Do i need to shown this sale in GSTR 3B?

2. If yes, Where should i show this amount in GSTR 3B.

Thanks in advance!