If you do not e-file then the only way for it to reach the IRS is if you put it in an envelope and take it to a mailbox.
When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.
When you mail your tax return, wait about 4 weeks and then check the IRS site:
https://www.irs.gov/refunds
(Keep a copy of the return for your own records)