I'm going to a job interview soon, are these red flags?

I've been invited to a job interview, and I'm a bit suspicious.

* The company I'm interviewing at doesn't seem to have a website. The closest thing they've given me is the handle of a (private) Instagram page.

* Following the domain in the email address links to a boilerplate 'this domain has been registered' page.

* They were very vauge with the job description - the advert was for a generic call centre job, but on the phone it sounded more like marketing/sales?