I signed up for deluxe package which is $40 why at checkout am I being charged $80 and how can I go back and select the FREE Turbo Tax

There are a couple of possibilities one might see an $80 fee.   You appear to be using Online Deluxe which is $40 for Federal and $40 for state. 

Or if you are filing only a Federal return, did you choose to pay the $40 Federal fee out of the Federal refund?  If so, that payment option has an additional $40 service fee.   That latter fee can be avoided by removing it and paying upfront with credit/debit card, or a prepaid debit card.  We can tell you how, if desired.  But if you want to start over, see the following.

TurboTax has 2 free products, but you are not in one of them.   I'll tell you about both products.

The regular Free Edition is for very simple returns and not everyone can use it.  Certain forms require an upgrade to Deluxe.   Did you start in Free Edition and had to upgrade?    If you haven't already paid or registered, and if you are sure you don't need Deluxe, you can use the "Clear and Start Over" feature to choose Free Edition.

https://ttlc.intuit.com/community/using-turbotax/help/how-do-i-clear-and-start-over-in-turbotax-online/01/26444

The other free product (TurboTax IRS Free File Program) is fully-featured and can prepare all the usual forms and schedules.  It is even more powerful than Deluxe.  But one has to meet one of the qualifications to use.  See below:

To qualify for free 2019 federal and state tax returns through the IRS Free File Program delivered by TurboTax, you just need to meet one of these requirements:

• Your 2019 household AGI is $36,000 or less;
• You qualify for the Earned Income Tax Credit (EITC); or
• In 2019, you served as active duty military (including Reservists and National Guard) with a maximum AGI of $69,000, and you have a military-issued W-2.

If you qualify for that program and want to use it, see these 2 FAQs:

FAQ:  What is the TurboTax IRS Free File Program?
https://ttlc.intuit.com/community/choosing-a-product/help/what-is-the-turbotax-free-file-program/01/...

and

FAQ:  How do I switch to the TurboTax IRS Free File Program?

https://ttlc.intuit.com/community/downgrading/help/how-do-i-switch-to-turbotax-free-file-program/00/...