#1. Please follow guide at: Managing Products

#2. Product data on your website is shared for all pages, so when you change a product, of course that product will be changed on the pages that use this product’s data.

If you want that home page to not use this data, you will have to create another product category, dedicated to it, then in the product display config, you will filter by this category.

Please find out all the issues before asking us a question