You can upload your website files using a FTP client program such as FileZilla (https://filezilla-project.org/) or WinSCP (https://winscp.net/).
Using these FTP programs you can transfer files from your PC to your webspace.
Add a new site in your ftp program with the setting below:
server: ftp.yourdomain.com
port: 21
user: *your cpanel username*
pass: *your cpanel password*
Once connected, navigate to your public_html/ folder and upload your website files there.
