Consider the 5 traditional financial statement assertions:
Existence
Completeness
Presentation and Disclosure
Valuation
Rights and Obligations Management.
Next, obtain a set of financial statements from a publically traded company (finance.yahoo.com or other). Select at least 2 balances on the financial statements. Describe the principal assertion of the selected account balance (existence, completeness, etc.)
Read this link to gain more information about the 5 assertions: https://pcaobus.org/oversight/standards/auditing-standards/details/AS1105