Local SEO ranking is influenced by how consistent your address listings are across the web.
Use targeted keywords that match the description of the service you offer. For example, if you are a business with a radius of operation that matches certain locations, use the name of the city and service you offer in the title and description of the page. When someone searches for the services you offer and they are located within small proximity from your business there is a great chance that you will be listed in that category.
The NAP stands for Name, Address and Phone Number. Search engines love structured data and anything that is easy to read for the bots. Here is the link to generate the proper makup for that. Make sure that you select either the JSON-LD or Microdata from the menu. Microdata will work fine but google has special affinity for the newer stuff which is JSON-LD. Next, fill out the form, copy it, and if you chose JSON-LD, place it inside the head tag on your website. If you selected Mircodata, you can put it in the footer as it will also display the information you entered.
Citations are just your business NAP but published on higher ranking websites. An example of the most popular would be Yelp And Yellow Pages. Simply list your business with them and you will be rewarded with additional links pointing to your website. This not only provides extra boost to search listing, it also gives your business extra exposure simply because there is many people browsing for what you have to offer.