Creating records in Nested forms

Hello

I have created a database where i should create and (table A) event that has date/location identifiers (fields) and each record has one to many relationships with 3 other tables - one of these tables…has one to many relationship with other tables…so in concept its a cluster database. the issue is that when i create a form to create a record for table A, the fields for the related tables does not show up, when I edit the field to show manually it looks as if its locked! why is this happening? and how can I fix it?

Thank you for your help in advance