Edit product page

Hi, I’m new to design a web page in erpnext and dont know how to custom the look of product page?
I tried to create a new web page with the same route as in web settings which is /all-products but that didnt change the UI in product page? and when you click the product can you also change the UI? for example in doctype Item there’s a web section which gives you a route to the product, can you change the UI for the route?