Interview nerves, what actually helps? - any advice?

I get tongue-tied when I am asked about my weaknesses. This is my first time dealing with any of this. The role is similar to my old job as a store manager. How do you prepare answers?

Arrive early, drink water and take a slow breath before you walk in. It sounds simple but it helps.

Thanks for writing this out. I went through something close to it last year, and it settled down once I kept a simple log of every call and form.