If you did not use a tracking service from the US Post Office when mailing the tax return you will not know if the IRS received the tax return.
The IRS has not been processing paper filed tax returns for several months due to the pandemic.
Go to this IRS website for information - https://www.irs.gov/newsroom/irs-operations-during-covid-19-mission-critical-functions-continue
We’re experiencing delays in processing paper tax returns due to limited staffing. If you already filed a paper return, we will process it in the order we received it.
Do not file a second tax return or contact the IRS about the status of your return.