I have three questions

Welcome to the club!

1. ProConnect is an input-driven software.  The input screens are generally organized based on the broad categories listed on the left panel, which are then organized based on major types of income, deductions, and credits.

Some of the input screens would have additional tabs for different types of input.  Watch out, however, for hyperlinks in tiny blue prints in the top-right corner of some input screens - these are easy to miss but you may need to click on these links to get to the additional entries.

State & Local have these own input screens, general separate screens for each state since the reporting requirements are different and many have their own quarks.  That's the first place I'd look for state specific entries.

There is no contextual help available in ProConnect but you will find hyperlinks on various input screens that will send you to articles about how to make inputs for certain forms and schedules.

If you are ever lost, try using the free text search box above the Table of Contents.  It can help you locate most (but not all) items and will bring you to the input page at best but not the field.

2. Diagnostic is found on the top menu called Check Return.  That's the item sandwiched between Input Return and File Return.

3. That's probably because you haven't yet populated M-2.  Check your input under Balance Sheet, M-1, M-2 > Sch M-2 (Capital Account).