Have you heard of Maslow's hierarchy of SEO needs? The theory is that you can't achieve the needs at the top without ensuring the more fundamental needs are met first.
Here's what it looks like:
Market/Product Research
↳ Website Design & Development
↳ Gather Contents (eg: Menu, Services, Portfolio, Blogs)
↳ Keywords Research
↳ User experience
Buildup Trustworthy Backlinks↳
Set up Meta (SEO) Tags, Descriptions, Alt Tags↳
Schema Markup↳
As funny as it may looks like, the bolded huge words are definitely the first few Steps you will have to achieve before targeting the rest. If you are serious about improving search engine ranking and website traffic or eager to find out more about SEO, HERE is where you can begin with.