Don't worry,do as i say.
If you know anything about AES Crypt,you can try it,it is a free download source.
https://download.cnet.com/AES-256-bit/3000-2092_4-10544070.html
I also recommend this one to you, but you need to pay a small fee to use it.
https://www.androidphonesoft.com/resources/password-protect-a-folder-on-windows-10.html