In AmE "lace the shoelaces" means to actually thread the laces through the holes in the shoes. "Tie the shoelaces" means to pull the laces tight and tie them in the bow that will hold them securely. "Knot the shoelaces" is not a common phrase, and referring to a knot when discussing shoelaces means that the bow was tied incorrectly and has come undone and now there is a
knot that needs to be undone before the lace can be re-tied correctly.