I am trying to build a website for my new photography business. I am trying to make the client experience as well as my own seamless and incorporate everything they and I need into the website (preventing links to third parties, anything that would take you off the website, etc). The basic idea I have is the website will have a sign in, from there they can access each project we work on individually and see/sign the project proposals/contracts/photo galleries, etc. directly on the website. I also want to gather the signed documents as well as contact information on a private page that only I can access.
Do you think that I can accomplish this on squarespace/shopify with integration provided by a 3rd party, or will I have to hire someone to code these functions?