My bro got the approval letter and the EAD in the same envelop about three days after the approval. I got my approval letter about a week after I checked my approval status from the uscis web site, the EAD came about 10 days later. So what I wanna tell you is, soon or later you'll have your EAD. Good luck on the rest of the steps.
As for the SSN, my bro's took about 6 weeks and I got mine in 5 days.
For a DL, I already got the permit, but I'm required to wait at least 6 weeks until I can schedule a driving test. I'm in PA.
For jobs, there are plenty descent jobs that requires only GED and no previous experience. Such as 911 call operators, entry level medical billing recorders, pharmacy desk helps, ect,. Just need to write a real good cover letter.
To build up your credit, everyone needs to start with a secured credit card. Ask a bankers for details.
Good luck everyone!