You are too late to use online TurboTax so there is no free way to file unless you use the paper forms and prepare them by hand. You missed the deadline to use the free software. Sorry.
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 received the return.