What would be the best practice to link multiple forms to one. Here some explanation in detail:

My application is for people to add their details and upload personal files, like a sort of personal CV.

Main form: Personal Details

form 2: Section Add documents

form 3: Section Add files

form 4: Section... etc

And a Page: to view all sections together and links/buttons to each section to add or update those.

Would be working with customer portal. Each user can login and should see only their file(s).

Looking for best approach

Question 1: 

Should each form get a lookup field linking back to the main form? And can that be based on the zoho ID field or better the user's email field? It's not that the user should see or lookup their data, it must automatically link them together.

Question 2:

For the Page view, show each section as a report of that form, but again only showing the user's records. How achieve that, would customer portal manage that or do I have to set a filter like showing only records from logged in user ID? Or their email? And how.

I am at the start of this. so any tips or guidance are vey welcome. Also if you can answer only part of the above.