I hope that the original thread jam has been cleared. The bobbin area of a Featherweight is intimidating but not difficult to take apart and put back together, fortunately.
As one of the younger members here, when I learned how to sew in 1990 on a new Elna I was taught to always hold the threads at the beginning of the seam. It was almost the only thing I did remember when I came back to sewing machines. I was surprised to find that it is apparantly not a Thing That Must Be Done anymore and people who learned to sew before I did and who have kept on sewing but are trying out vintage machines are caught by this. It is just one of those odd things, I guess.