Ashamed over old boots

I just got a job at an auto factory that requires steel toe shoes. I’m broke and the only pair I have is about 7 years old fake leather peeling and with mold spots on them I can’t get off from when I forgot them in the rain. I cleaned them off with a toothbrush and dish washing liquid but they still have the green and brown spots. Will I be made fun of over this? It’s a dirty factory, but I’m afraid I’ll be made fun of over them and given a hard time. Should I be worried?