DNS & FTP (question certainly easy for you)

Hello, I am new to CPANEL. Domain name: purchased from OVH with an account (which was already linked to another hosting) Server + new hosting: dedicated purchased from OVH with another account I put in the DNS A field: the IP address of my dedicated server As I did for my other areas (where everything works). I created an account for the domain on cpanel, like for my other domains (where everything works). I created an ftp account. When I want to connect to it I get the following message (FileZilla): "Failed to attempt to connect with" EAI_NONAME - No node name or server name provided, or unknown ". " Do you have any idea of my mistake? On my other domains it works. Likewise, when I create a subdomain via cpanel, will this subdomain be created on my OVH account which owns the domain? Or do I have to do something manually. I'm really very new to CPANEL and I'm sorry for these silly questions ... Thanks a lot for your help, Mikael