The profit and loss statement (P&L) answers one question: over a period of time, did the business earn more than it spent to earn it? It runs top to bottom in a fixed order.
Revenue comes first: what you billed customers in the period. Next is cost of goods sold — the direct costs of delivering what you sold, such as materials or contractor time on client work. Revenue minus those costs gives gross profit, and gross profit divided by revenue is your gross margin.
Below that are operating expenses: rent, salaries not tied to delivery, software, marketing. Gross profit minus operating expenses gives operating profit. Interest and tax come after that, leaving net profit.
Two cautions. First, the P&L records revenue when it is earned, not when cash arrives, so a strong month can still leave the bank account thin. Second, a single month is noisy; compare the same month last year or a three-month average.
Try this: take your last P&L and calculate gross margin for the period and for the same period a year earlier. Write one sentence on why it moved.