Hi Ricky,
More often than not, when we see this from a new-to-us client, it's because their previous SEO provider put some content on their homepage and drove 100% of the links there but did nothing for the other landing pages.
If you're comfortable dropping your URL in here I'd be happy to take a closer look, but if this is the case for your site, I'd suggest starting by boosting the content on each of your landing pages (to give you an idea, our internal expectation is 1500+ words of quality content per landing page, styled so it isn't a wall of text) and revise your upage titles, meta descriptions and headings as well.
Working on building some links to these pages will also help out quite a bit. Basically, the common mistake is to almost over-optimise the home page, ignore the rest and wonder why it's only the home page that ranks
Similarly, make sure your nav is as flat as possible and links directly to these landing pages rather than just from a broader "services" page or something.