WordPress is quite a bit more work and, unless you are an accomplished programmer, it will be much harder to configure well. it also needs regular maintenance to manage updates to keep it functioning and secure. Sometimes updates break your site which is why being able to code is important.
Alternatively, you can use WordPress and pay a monthly fee to a programmer to keep it stable. There are pros and cons to each. Also look at BigCommerce. It has dramatically stronger SEO than Shopify, more native features built in which will save you money.
My suggestion here is, there are a lot of great folks on YouTube who teach SEO very well. Great for beginners and a launching pad of sorts. You’ll easily get enough skillset to handle even the diverse complexities of SEO. Good luck and welcome to the world of SEO.