GST Filing on Quarterly basis

Dear Sir, I am registered with your website for filing GST returns. I am a first time user and have done one transaction of approx 14 thousand in the month of Dec'17 & now want to file GSTN1 with GSTN3B. I have created invoice which I have raised in the name of my customer Delhi Blue Pottery. This job pertains to custom clearance of import shipment at CFS Delhi & custom cleared by Balam Singh Bora. My busines name if Archer Global Logistics Final consignee is Delhi Blue Pottery Balam Sing Bora billed Archer Global Logistics (me) Rs. 9772/-in which GST is Rs. 1490/- I billed final customer Delhi Blue Rs. 13872/- in which GST is Rs. 2100/- Now my liability to GST is Rs. 2100 less Rs. 1490 i.e. Rs. 610.00 Should I need to file GST return as Rs. 610.00 OR Kindly advise me how should I go about this while filing GSTN1 &3B. How much GST I need to pay to GST department. I am unable to understand the procedure for filing and claim of the same. If you could help please. I shall be highly obliged to you. Best Regards//U.S. Chauhan Mob: [deleted]