Get yourself google adwords account and use keyword planner. Its a myth that someone does any work for $10 in SEO. There exist keywords with low search frequency and low competition, those are the most easy to rank (although, doubtfully you will rank #1 at once). In most cases, if you have a decent website with worthy content, you will enter TOP-5 in search without any help over a period of 2-6 months.
Be careful here, most webmasters/business owners are completely wrong about the keywords they wanna rank.
As for low comp and high search keywords, many think there is no such thing. There is. One of the example where you could find such thing: a regional brand or service provider that distributes its products/services on its own, without dealers. They mostly have to compete only with information keywords like "brandname reviews". You can wonder why would you need such a thing, but there are lots of twisted ideas out there.