Help with making costume Sewing Machines Parts and Sales in Los Angeles

I always end up waiting until mid October to pick a costume for Halloween. This year, I would like to make my own costume. I want to be Hercules (the Disney version with the blue cape) but I’ve very little experience with this kind of thing. Where do I start the process? I’m trying to give myself plenty of time. Are there patterns for this kind of thing? I DO have access to a sewing machine.