@morganwriter1gmail-com
I think you should be fine. I think most programs you download over the internet these days need a license key (which you get emailed to you) for it to work. If for whatever reason you lose your copy of the software, I’m pretty sure you can redownload and reregister with your same license (https://bombich.com/kb/ccc4/how-do-i-use-one-license-ccc-on-multiple-macs-in-my-household). Don’t take my word for it, and do your own research, but I’m pretty sure that’s how the system works (at least for that software).
But if you need to do what you’re describing (wiping your macs internal hard drive), you’re right, it makes more sense to do that first before downloading anything new.