At least in my area of practice (Los Angeles area), biometrics are done first. I would go to the interview, but if you are not prepared and /or do not have an attorney, I would ask for an extension and take the time to prepare for the interview both in terms of your oral testimony and your written supporting evidence.
Sometimes the Biometrics appointment comes after the scheduled interview. The interview should still take place but you cannot be given a final approval until the biometrics have been taken and are clear.
Samuel Ouya Maina, Esq.
Law Offices of S. Ouya Maina, PC
332 Pine Street, Suite 707
San Francisco, CA 94104
You need to attend your interview, and I strongly suggest you be as prepared as possible for the interview. Affirmative asylum interviews are typically the best situation for a grant of asylum. If you have not already done so, I suggest you hire an attorney to review your claim and prepare you for the interview process.