New to ERPNext in Ubuntu 14.04

I first install ERPNext in ubuntu 14.04 lts OS, It shows version 6.XX there is no GST futures so i update bench, now it comes error: 503 and Your system is being updated. Please refresh again after a few moments
kindly help and solve my problem

Can you post the console logs for when you ran bench update? Did it succeed?

We are on version 8 right now, so you probably need to update all the way to that (bench update --upgrade)