Fatal error: Class 'WPSEO_Options' after plugin updating

I received this error after updating seo yoast. I dont understand how I can be locked out of my wp and cannot do anything without that error popping up. I read posts where folks talk about deleting such and such in ftp. But, I dont know how to access or how to find the ftp. This is depressing. I just started this thing as an amateur- dont understand how you all manage. I just activated the wp last week! Very sad unreliability. Thank you anyone.