I need turbo tax 2020 personal and buisness

You can purchase past year desktop software from this site or you can also find it from various retailers.

Online preparation and e-filing for 2019 and 2020 and 2021 is permanently closed.

To file a return for a prior tax year

 If you need to prepare a return for 2019, 2020 or 2021 you can purchase and download desktop software to do it, then print, sign,  and mail the return(s)

https://turbotax.intuit.com/personal-taxes/past-years-products/

You may also want to explore purchasing the software from various retailers such as Amazon, Costco, Best Buy, Walmart, Sam’s, etc.

Remember to prepare your state return as well—if you live in a state that has a state income tax.

https://ttlc.intuit.com/community/state-taxes/help/how-do-i-contact-my-state-department-of-revenue/00/25573 

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.

Federal and state returns must be in separate envelopes and they are mailed to different addresses.  Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.

Note:  The desktop software you need to prepare the prior year return must be installed/downloaded to a full PC or Mac.  It cannot be used on a mobile device.

You can no longer use TurboTax Online to file a tax return for 2020. You have to use the CD/Download TurboTax software, which you can purchase at the following link.

File your 2020 taxes

It's not clear what you mean by "personal and business." If your business is a sole proprietorship, a qualified joint venture, or a single-member LLC that has not elected to be treated as a corporation, then TurboTax Home & Business is all you need. If your business is a multi-member LLC, partnership, S corp, or C corp, you need TurboTax Business (not Home & Business) to file the tax return for the business. But you cannot file your personal Form 1040 tax return with TurboTax Business. For that you also need one of the personal versions: Deluxe, Premier, or Home & Business.

Before you buy, check the system requirements. The CD/Download TurboTax software is only available for Windows or Mac. It cannot be used on a mobile device or a Chromebook. TurboTax Business is only available for Windows, not Mac. There is a link to the system requirements on the purchase page at the link above.