There is no interview involved. You apply at the VAC for Spain which is called BLS International, located at Unicentro Plaza, the one across from El Nacional Supermarket. To apply, Spain should either be your country of entry or where you´re planning to spend the most time on your trip.
You make an appointment online
https://do.blsspainvisa.com/spanish/ and on the date of the appointment you deposit all documents, It is also there that you pay for your visa fees. Now, before you make the appointment you have to fill out a visa form, so you should have all the information available before you start, but you can still bring a new form on the date of your appointment. There are multiple visa fees, depending on the appointment category. You also have the option to go to the center to pick up your passport or have it delivered via a courier service.
I'm Dominican and currently have a two year visa but started with shorter term visas. My first visa was 6 months. My husband´s first visa was only one month. I´ve done applications for relatives, friends, and clients, and what you get is usually in between your travel plans and whatever the consul thinks is appropriate.
You´ll need evidence that you´ll have a place to stay there. If you don´t have an invitation letter, you can solve it by providing a hotel reservation. I used confirmed hotel reservations from travel agencies. You´d also need a plane ticket reservation. It´s only the reservation, not buying the plane ticket.
Let me know if there´s anything else you´d like to know.
