whether or not you count the turning chain can depend on the pattern. Most patterns I read say to count the turning chain (of like Ch3) as the first stitch. Then you move to the Next set of loops to start. There are patterns where the turning chain is not counted as the first stitch, but I've mostly encountered that in round patterns, rather than squares/rectangles.
and about going into the foundation chain- if you chain loosely, it is easier. (it should look kinda loopy) If you add a row of sc before you start the pattern, it shouldn't matter too much, but just be aware and be consistent. you want that sc row to have the correct number of stitches to start the pattern.
there are so many ways to hold and wrap- whatever works for you is fine as long as you always do it that way....
did I say one project at a time?