coolkid

As Ms Hoagn said, the notice tells you to wait for the biometrics letter in order to follow your case online.
That being said, don't hold your breath too long waiting for your case to update. I had good luck with my notifications but others NEVER see any updates online, even after receiving their green cards in the mail. Some people even start to receive updates AFTER getting their GC. Not exactly useful.
Good luck!

Your NOA1 receipt number won't work. You will need to wait until you get the biometrics appointment letter. That one will have another case number on it and you can use that to check your status. If you read your NOA1 you will see that it says that right on it. It says that once you receive your biometrics letter you will be able to check your case status online.

Of little consequence, be sure to make a copy of your originals for your files.

IMO, keep the originals in your possession and send copies. If any entity needs an original for whatever reason, they will ask for it.

I would never send any originals to USCIS unless it specified that they need original of certain document only (like marriage certificate for AOS). I'm sending photocopies only, papers can get lost in the mail or in USCIS facilities so I might need originals on hands in that case or for the interview.
- Victor from Russia

Never needed to show my SSN when i got my job they only asked for my green card or AED. My SSN still says only vaild with ... but never had any issues so far.

You don't really need to (and SSC isn't required for your 751 package), but if you'd like for convenience when applying for jobs then you can.