Well, SEO is all about optimizing your content and code.
First thing to work on when the code is ready is content, no content no search matches
So this mean new content added on a regular basis and well organized.
You need to target the first keyword to work on and provide content about it. This can be a long run starting from scratch, but it's the first thing to do.
Then, work on backlinks, try obtaining good one on related web-sites, and never stop
Once you'll start having the first results, you'll be able to accurately track which are the keywords or key-phrase providing the more visits and work on optimizing them as well, as they could be out of what your first expected as keywords to work on.