While you should be using keywords for your site, do not fill your site to the brim with keywords. Search engines such as google have sophisticated system that can determine between a normal sentence typed by a human and a sentence filled with so many keywords that it feels artificial. The more human and realistic your content sounds, the better the chances are that it will achieve a higher rankin the SERP.
When using SEO on your site, don't forget about organizing your files in the directory. The more layers you have in your file directory, the less weight the search engine spiders will place on those pages. Organizing your files to be closer to the root directory will help to boost your rankings.
To make your website more "crawl-able" for search engines, you should ensure that your website has a complete site map. If you do not know how to make one, you can find free site map generating tools online. Making your site more search engine friendly will give you a better chance of increasing your site's rankings.