The location for FTP credentials differs from web host to web host. You will need to contact your web host to find out the FTP credentials for your account. But we have created a few quick videos on finding FTP credentials in DreamHost, SiteGround, 1&1, Hostgator and GoDaddy. Kindly take a look.
Quick tutorial on how to find FTP credentials
SiteGround
1&1 Hosting
HostGator
DreamHost
GoDaddy