SEO for my shopify store

I've recently launched a shopify online store in New Zealand and I'm starting to work on the seo side of the business.

I'm using SEMRush to identify some keywords to target. Fortunately the competition are barely doing any content marketing or seo so I think I have an opportunity to dominate this niche with organic traffic.

If I'm trying to target a keyword, such as 'keto snacks nz', should I use the keyword in my collection pages, product pages and also write an article about keto snacks? Should I do all 3 or just focus on one to target that keyword?

I'm trying to develop my seo strategy and I'm a bit confused with all the research I've been doing.

Do you have some advice on the best way to target specific keywords for my niche?