Looking to create completely custom product page - how can I create an Add To Cart Button?

Hey guys! I am about to add in some digital products into my site, and I am wanting to create a custom product page - If I could give an example it would be: https://www.wildflowerdesignco.co.uk/brand-strategy-guide in terms of the seperate sections (my design will be considerably different for obvious reasons as its a similar product I am selling).

Two questions:

Is it possible to create a custom product page just like any other page, but link it as a product page (in terms of having the shop landing page, and those 'products' inside of collections, linking through to these custom pages)

and then how do I add a - add to cart - button inside this custom page?

Thankyou! I have searched as best I can but a lot is just customising the basic features of the included product page styling SS uses, but I think I need additional sections 🙂

Thank you so much Paul!