"Do you have a resource (article, book, etc) of how to build a trial balance"

Every account (activity or category) has an ending balance that is the total for the year (income and expense) or the final position of that account (bank, loans, credit card, etc).

You cannot use income and expense, only. Not all inflows are income and not all outflows are expense. Do they not have a Balance Sheet? How did they generate what they gave as income and expense? If they use a bookkeeping system, it should have the reports you need. Look for things like principal payments posted as expense and sales tax posted as income, for common errors.