SEO involves many different aspects of website building and marketing:
Keyword research and page optimization
Keyword research determines what keywords related to your business are actually being searched by real people and how often. This information can then be used to create / optimize pages on your website, any new content you add, and your website listings (if you have any citations yet) for those keywords.
This can be done without keyword research but we’ll just be guessing at which keywords to use in the new content. Content can be pages, articles, graphics, ads, etc that are added to your website. The more content, especially content with good keyword phrases and themes, the better for your visitors and for google ranking.
Paid search ads (Google Adwords / Bing Ads - aka Pay Per Click)
The quickest way to put your site high up on the page in Google results. This includes keyword research, competitor research, ad creation, landing page creation,and monthly optimization of your ads to reduce spend and get better results for your money. Costs include initial research and setup $1000, as well as monthly fees for optimization and reporting, and ad payments to google - you can set your own ad budget.
Adding your site to directories (citations)
This means getting your website / business listed in online directories. Listings are one of the MANY factors google looks at when deciding how to rank your web pages. The more good listings you have with reputable directories, the accuracy of your contact info on them, and additional content of the listings (descriptions, images, hours, etc) all help you with google (and people!).
Adding social media is a good way to have more listings - a Facebook business page, a Twitter page and an Instagram page are good ways to get more links, even if you don’t use them yet.
SEO is an ongoing process. The best way to handle it is to figure it into your monthly marketing budget and keep tabs on all aspects of SEO.