Here are some top SEO tips to help your Shopify store rank well.
1. Create a Site Hierarchy
2. Use Data-Driven Keyword Research
3. Optimize Metadata
4. Add Alt Text to Images
5. Start Blogging
6. Incorporate Video and Engaging Media
7. Optimize Site Speed
8. Improve User Experience
9. Optimize Product Pages and Descriptions
10. Optimize for Mobile
The best thing for you to do as a beginner is simply to Google/YouTube search "how to do SEO" and spend a couple of hours understanding the business.
Then, you can move on to paid services to know exactly what you're paying for.
You can see some of the good services here on the marketplace or you can search like a query on Google as you will see some great options. Besides buying some service, take care that you also work on good SEO practices on Shopify, optimize the structure of the site, take care of product pages, compress images, don't use too many fonts, add meta-tags and title tags on all pages, and alt-tags on all images, interlink the pages, check some plugins for additional suggestions, and similar.