I went to US on F1 in Sep 2014 and I left US in March 2015 and have been living outside US since then. Now I intend to travel back to US with i20 from a new university ( sevies transfer is completed ).
Is there some timeline before which I need to go back to US ?
My F1 visa is still valid so can I travel on the same visa ?
What all documents I might need at the port of entry ?