Static html to wordpress upgrade

I want to convert my html site to wordpress. The problem is, I also have a blog on the back end of the site. The blog on the back end is in a directory called mysite.com/blog

I want to install a new blog on the front end mysite.com/ and use the database of the old blog. Then add the static html pages to the new blog. It’s too time consuming to manage about 40 static html pages and I want to take advantage of all the power of WordPress for my site.

I thought I could just install a new blog in the root folder and change wp-config.php to call data from the database of the old blog.

I tried but it didn’t work. I never thought to upgrade the old blog first so maybe that is where I went wrong. I have a couple of questions.

Should this work?
Is there a better solution?

Thanks