Gst returns?confused pls help

sree harsha (ca-final) (845 Points)

07 December 2017  

i have filed gstr-1 for july on December 1st,now i am trying to file gstr-2 which is not filing due to timeline and gstr-3 window itself is not showing in portal,as per notification no.57 due date for gstr-1 is december 31st.my queries are:

1.as previous due date is october10th for gstr-1 and i filed on december1st will i able to face penalty?

2.when can i file gstr-2 and gstr-3 for july?

3.can i file gstr-1 for august and sepember now?

4.shall we file both quarterly and monthly GSTR-1?