How to improve keyword ranking from 3rd or 4th page to first page?

Your website looks fine. If you really want to make your website visible in top results then avoid the older and outdated SEO strategies and try to build high authority backlinks with no content duplication. You may do guest posting on high authority websites related to your industry. I know it is a time consuming process, but this will give you the long lasting results. Also work on its traffic by regularly updating the interesting posts in social media sites.