I think it's a great start for your store. The product images are clean and the site nav is well organized too.
1 feedback I would like to give is that you can make sure all the product images are squares. This would make your store look better as your products will always be in a clean grid and won't move up and down
Wish you all the best and hope your store does well.
Welcome to the Shopify world! I really like the layout and the theme chosen for the website. It highlights the products really well. Being a matcha lover myself, I really liked the catalog as well.
I had a couple of points to make here. Adding them below.
In your product catalog, you could add some kind of stickers or labels to highlight things like green, organic or pure etc. The Shopify app store is source of some really good Apps that can give your catalogue the focus it really needs. You can highlight some of your products to bring more attention to them.
Wish you all the best!