SEO Website Audit
The first place to start when coming up with an SEO strategy for a website, is an SEO website audit. That way, you can get a good overview on exactly what is doing well/badly on your website, SEO-wise.
In the SEO audit, you will learn about what keywords your site is already ranking for, what backlinks are pointing towards your site and how your site is performing in a technical sense. The SEO essentials will be checked and advice on how to fix them will also be given.
The end of the audit will provide an SEO strategy, or plan of action for how to proceed based on the audit results.