I agree with Mike...create it as you learn. You'll always be tweaking and improving as you go along. This is not a race but a marathon and nothing happens overnight...trust me. Find a niche that you're passionate about and try different themes to see what fits best. It takes awhile for you to be considered an authority in your chosen niche so add good content while taking the lessons and you'll be happy with the results.
Good luck and welcome to WA
Karen

As you go. Get your content marinating in Google as soon as possible.

You can always, and you will always, be making adjustments to posts and your website in general.

I hope this helps

Mike