FTP cannot connect

I’m a newbie in wordpress and i would like to know how to use Filezilla. I have downloaded the software, installed it, followed the instructions on the support page and yet i am unable to connect.

my ftp screen just says ‘unable to connect’. hmmm. where’d i go wrong?

i am interested in using filezilla because i want to change the layout on my wordpress blog. i can only change the layout when?

also, i saw something about hosting providers. what is that? it means that i have to have a separate host, not wordpress?

thanks for answering this!