A trial balance lists every account you have and what it holds, in two columns. It is the first thing an accountant asks for, and the quickest way to see whether anything has gone sideways.
Find it at Accounting → Trial Balance.
Reading it
Accounts are grouped the way they appear on your statements: assets, liabilities and equity first, then revenue and costs.
Balance sheet accounts are cumulative through the as of date, because a balance is a position — what you own and owe on that day. Revenue and cost accounts cover the period you set, because an income statement is a stretch of time.
The basis switch changes the profit and loss half of the page and leaves the balance sheet half alone.
When the columns do not match
Total debits and total credits are supposed to be equal. When they are not, the page tells you which of two quite different things is happening.
If your books are fully double entry, a difference is a real problem worth chasing. It usually sits in opening balances or an unreconciled entry rather than anywhere near revenue.
If some of your figures come from a bank feed, a difference is expected and is not an error. A bank feed reports one side of each transaction — the money moved — and the account it moved through is not recorded as a second posting. The page lists the sources that report one side only, so you can see exactly where the gap comes from.
Journal entries you post and transactions from QuickBooks carry both sides and balance on their own.
Giving it to your accountant
Export CSV gives you the whole thing as a spreadsheet: account, type, statement, debit, credit, with the totals on the last row.
If an account looks wrong
Open Accounting → Journal Entries and filter by that account to see everything posted to it. From your general ledger, the Debits and credits panel on any line shows both sides of that transaction.