I’m not sure what you saw here. There are no daily FTP limitations. Could you maybe share the real error message that the FTP server returns?
Uploading a backup should be pretty straight forward. If it’s a .zip file or another archive format, then extract it first. Then, upload the extracted files and folders from your computer to the htdocs folder of your site.
Looking at the counters in the control panel, the account is nearly empty.