1. Open Filezilla
2. Go to Site Manager
3. Add New Site
4 Enter Domain name in Host
5 Port : 21
6. Protocol : FTP
7 Encryption : Only use plain FTP
8. Login Type : Normal
User: Enter cPanel Username
Password : Enter cPanel password
Now Click on Connect
At right hand side it will show you folders of server side.
In case of linux hosting, you need to upload your files in public_html folder
in case of Windows hosting, you need to upload your files in httpdocs folder.