Questions about a potential SEO team.

I am coming on here to ask questions on how I know this company is good or not. So I have a friend I've known for around 2 years, he works with SEO specialists blah blah. They are local so I met with them in person seemed fine etc. But the more and more I go forward my gut is just telling me something is off here. Any tips on finding out about legitimacy? I just need mostly a website right now I can handle most of the back-end seo work. All answers of any kind would be very appreciated thanks for reading this post.