FileZilla is one of the most frequently used FTP clients thanks to its rich-featured and user-friendly interface. You can download the latest stable version available from their official website from here. Now you can install FileZilla and open it. After that you will see its default screen in which you need to enter Host, Username, Password and Port.
You will need to type your domain name in the Host field and 21 in the port field. Username and Password are the same as your cPanel login (Control panel) ones of your account with ZomboHost.