Getting your pages to rank well on search engines is a tricky task – there are lots of aspects which go towards the ranking algorithm which Google et al use. It is important to separate the different aspects first.
The content of your pages is one of the most important factors. You need to have plenty of content – aim for around 800-1000 words per page if you can! This way you can include plenty of keyword rich phrases to boost the relevancy of your site.
The heading tags are crucial to let Google know what your page is about. You should have exactly 1 H1 tag and several H2 tags to support the H1. This is the way search engines read the page to see what the topic is.
These are also very important for search engines to read in order to rank your page. Make sure you have an optimised title tag, which allows both bots and real users to understand what your page and site is for. The description should be your sales pitch!