About to HIRE a Virtual assistant for my friends ETSY and Shopify business, need your feedback regarding few questions.

What questions should i ask in the interview? What's the best place to hire people from? What are the red flags that i should be aware of? How do i ensure timely compliance and quality work remotely? How to monitor performance,should i keep weekly assessments? What would you recommend? What should be the average weekly salary and weekly working hours?