Couple of thoughts ... If this structure is attached, you may need permits. (Many people ignore such requirements). If ti is free standing, you need angle braces from the posts to the roof joists for strength and stability.
Since you have existing concrete, I woud suggest a Simpson E-Z Base. This is a metal "box" that is tied into your concrete and the post drops into the top of it. It helps with lateral support in both directions. It also allows you to remove and replace a post if it rots.
How about sharing your design for feedback? GOOD LUCK on your project!