As a sole trader or a small business, you can't do everything at once. You don't need to. Good SEO for a small business comes down to a few right choices that make it easier for the customers already searching for what you do to find you.
Do this first
Fill it in completely, verify your location, keep your opening hours up to date and reply to reviews.
Connect your site to Google Search Console, free of charge. It shows which search terms you appear for and which pages are in Google.
Don't put everything on one page. A page for each service makes clear what you do and where you do it.
Make it easy to contact you: a form or phone number on every page.
When time is short, these are the things that bring little in return:
Outsourcing pays off when your customers search Google for your services and you notice you never get round to the work yourself. At that point, it makes more sense to hand the work to someone who follows it up every month.
At VARAMEDIA you start with an online briefing about your business, your services, your area and your branding. Keyword research follows, and then we make a proposal that fits your market: a small site for one region is a different job from a site in three languages. We don't publish prices because the scope varies so much. What the price depends on is explained under SEO pricing.
Do you work locally? Then local SEO is probably the first thing to work on.
Let us know what you do and which area you serve, and we'll tell you honestly which first steps are worth taking.