Most likely the Recruiting Centre or unit Recruiting Office submitted for a Reliability Status screening, which would allow you access to designated material, but not classified material. Basically, it confirms that you are reliable enough to be employed, but not much else. Depending on your trade and the requires of the position you fill on the Automated Establishment Report (AER) you may be processed for a Level I, II or III clearance.
Now, it is also possible that they have put in for a Level I, II or III clearance immediately, but that isn't SOP. The long and the short of it is once either the Reliability Status or Level I, II or III is granted, you will be briefed, advised of your duties and responsibilities and carry on from there.
Bit of advice though: never sign documents you haven't read or don't understand. At the very least, make sure you get a copy of them and read them later.