I've done quite a bit of fiberglass boat repair, and I agree with the others. Get another ladder. It will be safer and much easier than trying to repair the one that you have. Fiberglas gel coat is time consuming, involves working with time dependent epoxy mixes, and a spray gut that will likely be trash when you finish the job, not even considering the cost of materials. Uou will save money, time, and have a safer ladder by just replacing it.
Never just take a possibly unsafe ladder to the dump, as someone might try to use it. Cut the ladder into several short sections before disposing of it.
Central North Carolina