Download the ftp client program, the best such program i know is Winscp, it is the best FTP client so far i know, you should use it for your own good, you can read the short review here.

You are gonna need some configuration that your hosting given to you, you need the server host, username and password, that's all you need. Host can be a domain name or IP address. If you already have all the configuration, you can now open Winscp Ftp Client.

1. Click new connection and add new site, then fill the inputs with your configuration you have.

Winscp connect to server

If that configuration not working try to change FTP Protocol from SFTP to FTP. And that's still didn't work, try change FTP protocol and port to another, you can contact and ask to your hosting provider. I've been using Namecheap and they have good customer services, i write short review about Namecheap here.