First start the SEO from on page technique:
search the relevant and important keyword
Write relevant meta title and meta description for each page.
Write Header tags H1, H2, H3 primarily.
Use all important tag.
Update ALT tags to all images.
Create Update 404, 302, error page.
Check broken links and fix it.
Then start off page technique:
Search engine submission
Free web Submission
Update blog and promotion on social networking site like as google, Facebook,Twitter....