can't access or download backups (trying to migrate websites to a new server)

so i have a brandnew install of virtualmin/webmin on a brandnew vps running centos

i have an existing server also running centos and virtualmin/webmin.

i did a backup of a single virtual server on my existing box and was then gonna download the backup file to my local computer ... and was then gonna restore it to the new vps

the problem is when i try and download the generated backup file to my local computer i get errors that the file and directory don't exist (even though i can see them) and that i can't download the backup file because of permissions.

i tried changing the permissions but that didn't help.

also i can't delete the backup files from the existing server ... because according to the error messages the files don't exist (again even though i can see them)

i've never done server migration myself so i'm new to this ... i have about ten sites i want to migrate to the new vps ... is there a better way to do this?