Round 1: Yes, repeat the pattern stitch (2dc, ch2, sc) until you get all the way around. Once you make it around, close off the round by slip stitching into the 3rd chain of the very first ch3.
Round 2: No, do not sl st into each chain. DO make a sl st into the space created by the first ch2. Then (ch3, dc, ch2, sc) into the exact same space that you just worked the sl st in. Now skip to the next ch2 space and work the pattern stitch (2dc, ch2, sc) into it. Continue doing that until you get back to the beginning of round 2. Like before, close off this round with a sl st in the 3rd ch of the first ch3.
Repeat round 2 until desired length, finish off as described, and then you will have yourself a slouchy beanie!
Good luck! And ask if you have any more questions!