Since you have a relatively small pool, the seasonal methods are slightly modified. I'm assuming the adjustments you made were from scratch correct? If so, here's what I'm seeing by using the Poolmath Calculator for your 2K gallon pool:
CYA - To go from zero to 40 ppm required 11 ounces of stabilizer. If any of the granular stabilizer did not dissolve, simply try to keep it moving around, vacuum it up, or sweep/net it up to avoid letting it sit still on the liner.
FC - Adjusting FC from zero to 4 would be about 12 ounces (1 cup & 4 ounces).
pH - in the mid-7s.
You say you SLAMmed your pool? Why? Was there algae already? I was assuming this was a fresh fill. Seasonal pools do not get SLAMmed, you just replace the water and scrub/clean it. If this was a fresh and clear new fill, there is no need for a "SLAM". Also, since this is new water and you added the programmed amount of stabilizer for a CYA of 40, there is no need to test CYA at this time. Just consider it at 40. FC only needs to be around 4 ppm, which should be measurable by your 2-way kit. No need to go any higher. If your FC is over 5 at the moment and the water is clear, the sun will burn-off the excess and the FC will drop soon. Make sure to never let the FC drop below 3 or else that's when algae can come into play.
Safe to swim? Yes if water is clear, pH is in the mid-7s, and FC is not above 16 which I doubt unless you added more than a quart of bleach.
Hope this helps.