That is a really good question and one that we get numerous times daily now.
Go through your bank statements- generally these were received in early 2020 and between December 2020 & January 2021. We must know amounts for both of these payments to ensure your tax return is not rejected causing delays and possible additional fees.
Go to irs.gov/payments/view-your-tax-account. You will click on Create or View Your Account then either log into your existing account or create an account. For security you will be asked questions that only you should be able to answer.
Call the IRS-The IRS IMPACT PAYMENT PHONE NUMBER is 800-919-9835. You will be able to speak to a live representative about your stimulus check.