Dividing the plant at this time poses NO problem. Just dig the hole the same depth & wider than your transplants. then cover them & water... most of the plants start growth in the spring & will give you flowers. IF your friend should give you some seed then plant them in the area you want the plants Cover the seed & water. again will have plants /flowers in the spring.... Reamber there are annual & perennial hollyhocks....

I have Old Fashion Barnyard Mix Hollyhocks. Are they a perenial or biennial? Do I nned to save the seeds or will they replenish themselves each year?

I would save a few seed from the old fashion hollyhocks just in case but I would expect them to replenish themselves.

Hollyhocks are one of the things that will come back year after year out in the Great Basin of Nevada and Utah where the sage brush and tumble weed are sparse and sickly.