We took the strokes # 1, 2, 3, 4, 5, 6, 7, 8, 9 and combined them to create all the letters.
If we look at a, we see that if we combine #7 + 8+ 3= a . Look at the exemplar that says Copperplate Stroke Sequence.
Follow each letter to combine the strokes you have be practicing to create the finished letter. There are no strokes that you've practiced for: k, r, s, z. X is like a #4 that the first stroke is diagonal rather than parallel then you can do the 2nd stroke from bottom to top. Just look at the exemplar and follow each letter. Don't combine into words yet. Use whichever nib you want and label your paper so you know what you've used. Be sure to label your nib identification chart after you've used each nib so you can teach yourself which nib is good for what. You will need to learn and remember this as you work on envelopes and other papers.