There are 2 methods available for doing this.
The easiest and best method is to use a FTP client like FileZilla or WSFTP and configure your session in the FTP Client. You can use your control panel login for your FTP login, see the Hosting Welcome email with details. If you have a paid hosting account you can additionaly create new FTP logins for your use.
Your other option is to login into your Control Panel and upload your files via the File Manager application, this process is longer and more tedious.Â