Keywords are words or phrases you include on your site, so that your site will show up when someone searches for those words in Google.
The main kind of keyword you want to include in your page is your business type, followed by your location. (e.g. upholsterers Sydney, or wedding planners Manhattan.) That's what potential customers will probably search for in Google.
It's extra-important to include your keywords on your site's main page, and in page titles and headings. (While you're editing a page in WordPress, click the Paragraph drop-down box, and make a few appropriate Heading 2's.)
You're never going to rank highly for some major keyword, like driving instructor, or even driving instructor (your city). There are thousands of competing sites that all want the same thing. You'll likely find that you end up ranking well for (and getting most of your visitors from) longer, more specific variations you happen to mention on your site, like experienced driving instructor or driving instructor (your suburb).
You can't game this system. Just mention your keywords once or twice per page. There's no extra value in degrading your site by stuffing your text full of keywords.