>>Yes, all taxpayers haiving GST registration are required to file GST return on the 10th, 15th, and 20th of each month. Even if there was no business activity or transaction during a month, the taxpayer must still log in to GST portal and file GST return to avoid penalty.
>>GSTR1 Outward Supplies 10th of the next month
GSTR2 Inward Supplies 15th of the next month
GSTR3B Monthly return [periodic] 20th of the next month
>>You can file your return by your self or by your near by CA.
>>you can get all details regarding due date of GST in GST portal.