You can try to do SEO on your own. Read here how to do it the right way. If you use professional SEO tools, you can do everything right. It's not very difficult, but if you have no time for it, you can hire SEO specialist. First of all see other project that he had, check their positions in Google, see the changes in organic traffic flow. If website's traffic increases and the spam score of the website is not high, then SEO specialist is good.