So first thing to say, you actually need to do keyword research. There’s no real way around this.
At its most basic level, it's sitting down and thinking about what your customers type into the search engine to find you or the product they want. So you need to come up with a pool of keywords and phrases that your ideal customer would use, and then decide on the top one.
So for example, if you sell an extremely popular brand like CHEWY blue denim, that might be a good one to focus on. HOWEVER! You also want to think about how much competition there is for that keyword. Because if everybody is trying to rank for that keyword, it's going to be harder for you to rank for it.
And on the flip side, if you go too niche that no one is actually searching for it, it doesn't matter if you rank first for it, because no one is going to find you if they're not out there looking for you. So you have to balance these two things: search volume and competition.
Other key points to mention on keywords… Definitely avoid keyword stuffing. An example of this would be overusing the word, using it in inappropriate places so that the meaning is totally distorted (just to use the keyword), and using white text on white background. Google HATES this kind of stuff.
And it’s unnecessary too! On Shopify, there is an SEO section where you can add your keywords. But you don't want to just paste that into every single page! So pick one keyword per page, and don’t repeat them. Each page needs a unique keyword. And if you do this intentionally, Google will see that you’re the expert!So the idea is to use keywords to signal to Google and demonstrate your expertise and authority in that area so that Google recommends you!