Writing about food/wine- anything I should know?

I started a job at a wine shop/wine bar about two weeks ago. In my cover letter/ interview I told the owner that I was interested in working there because I want to learn everything I can about food and wine and maybe become a food writer someday. He just said that I can write up some marketing materials, which I think is so cool but now I feel really out of my depth. The other staff members definitely know more than I do about beer and wine.

We’ve had tastings and everyone was making all these educated comments about what the wine tasted like, and I’m starting to get the hang of that. I guess my biggest worry is that my subjective tastes will be different from what is “right” or generally accepted, or that I’ll just come across as not knowing what the hell I’m talking about. I’m writing up a few bottles that I’ve tasted and researched. How can I

1) calm down and
2) write like I know what I’m doing?

Eek. I’m so intimidated.