I previously had a photography business that I stopped a few years ago and stopped paying for my domain, host, etc. I would like to start that business back up again and I would LOVE to be able to use my previous website template, as I put a lot of time and work into it. I have a "Website Backup" folder on a hard drive and I am hoping I could use this to re-create the base of the website, but have no idea where to begin. It was on WordPress before and I would like to do the same thing again, but if I buy a new domain do I just get the option to upload the files? And which ones would I use?

Did you take a backup of the database? I’m not seeing an SQL file. Without that, you have nothing.