If you never received the EIP1 or EIP2 then when you complete the 2020 tax return you will be eligible for the Recovery Rebate Credit reported on your Form 1040 Line 30.
However, you should check your tax account on the IRS website to verify that the IRS did not send the stimulus payments to you already - https://www.irs.gov/payments/your-online-account
To complete and file a 2019 and 2020 tax return using TurboTax you will need to purchase, download and install on a personal computer one of the desktop editions for each tax year from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
Prior year tax returns can only be printed and mailed, they cannot be e-filed.