Webserver help needed

[Hitman]

Hi all
I bought some webspace at Cheap, Affordable Web Site Hosting Packages, Services and Plans and i have access to it through an ftp program.
I had to buy a domain name elsewhere as they dont do them at hostdogs so i went to https://www.uk-cheapest.co.uk/index.php and purchased my domain name there.

Now i just cant figure out how to point my domain at my webserver.
At uk cheapest domain management page i changed the nameservers to the hostdogs configuration

It does not seem to let me use custom dns records.
I can point my domain at any website.
I cant point it to my ftp site as i dont know what the address is.
Im a complete noob to all this webserver stuff...any help would be appreciated as im still scratching my head.
Ps ive contacted them but replys are slow....tearing my hair out