Guidance to start my small biz in F&B

Hello, people who are running their side hustle in F&B category, I wanted some guidance on how to start. I have an idea about the product and category, also have a few wholesale suppliers. But I have confusion on how to start?

1. How did you validate the idea?
2. Did you choose to source from supplier and white label or directly made your own product.
3. How did you get your first customer?
4. How did you sell/market?
5. Did you make a website or started on WhatsApp?

As a person who is willing to start but have no personal connects who can guide, I am reaching out the community here.

Thanks in advance!