Learn the basics of SEO: Here's a beginner's guide
Links: get listed on some directories. Check address listings for consistency. MOZ Local is helpful - https://moz.com/local/search
Indexing: get your site indexed on Google Search Console. You can sign in with your gmail account.
Content: the more content your site has, the higher it will rank. The more pages the better, but you want a decent amount of content on each (ideally 1800 words, but over 500 is ok). Add specific pages for each service you offer and a page with local info for each town/city you want to rank in. Here's some more ideas
Competitor research: see who's ranking for the keywords that you want to rank for, click on their websites and get some ideas.
A great website gives a great first impression but doesn't do any good if no one can find it. With any website, you won't get to the top right away. It actually takes a lot of work! You can do SEO yourself, it just takes a while to learn it.
Want to learn more? Here's a guide to the Top SEO Ranking Factors in 2019 (We have to stay updated because it changes all the time - Google likes to keep us on our toes!)