Third stimulus https://ttlc.intuit.com/community/tax-topics/help/how-will-the-stimulus-package-impact-me/00/1393859
Note, In particular, getting the new (expanded) child tax credit has nothing to do with filing your 2020 tax return. Whether you already filed, file now or file later, the additional money will not be part of your 2020 tax refund.
For the unemployment $10,200 exclusion, you should wait for the IRS to issue instructions. See https://finance.yahoo.com/finance/news/claim-10-200-unemployment-tax-213344752.html
The increased Child Tax Credit is effective in tax year 2021, not for tax year 2020. Any advance on the Child Tax Credit in 2020 will be handled by the IRS.
You will probably have to amend your 2020 tax return to get the unemployment compensation exclusion. But not until the IRS provides guidance.
After the legislation has passed Congress and after the President has signed the legislation and after the IRS has written the rules, regulations and procedures. And after the IRS has changed any forms or schedules to accept the tax code changes. And after the IRS has approved the changes in the TurboTax program that apply to the tax code changes, then it will be available for the users of the tax preparation software.
This can take anywhere from several weeks to several months before it becomes available.
See this TurboTax support FAQ for information on the American Rescue Plan - https://ttlc.intuit.com/community/tax-topics/help/how-will-the-stimulus-package-impact-me/00/1393859