Migration from Microsoft.Azure.DocumentDB to Microsoft.Azure.Cosmos package with current class library in .NetFramwork 4.7.2

[Sanjay-wow]

In my current project, the class libraries are in .Net Framework 4.7.2 with Microsoft.Azure.DocumentDB package. I have migrated from DocumentDB to Microsoft.Azure.Cosmos (3.29) V3 SDK. But

Questions:

1. After migrating getting errors in many places like "inaccessible due to its Protection Level ".
   Example: have "Protocol" in a class file, when I go to its definition it references to as an internal Protocol (Metadata). Then it shows an inaccessible due to its protection level error.
   So how to solve this Protection level errors, any suggestions pls?
2. While migrating to cosmos, do we need to consider .net standard 2.0. if YES, what is the procedure with .net standard pls?