If you are interested in editing the categories list in the page title on the shop page as shown on the screenshot https://gyazo.com/22202043fea9e14c600061c34caad878 then it is not a standard WordPress navigation. It displays all the categories in your store. But you can exclude unwanted categories from there. Find this option Theme Settings -> Product archive -> Page title.
Could you please clarify what you mean by “flowers block” in the header? Send us a screenshot, please.
We would kindly ask you to change your review on ThemeForest as the related issue was sorted out. We are still here to provide you with all the necessary assistance. Thank you for understanding. https://themeforest.net/downloads