IF I PAY NOW FOR TAXES PREPARED BY YOU, WILL THAT AUTOMATIC FILE THEM

After you file

If you pay for the TurboTax product it does not automatically file your return.

The last tab you will go through will be the File tab
Step 1 is where you will pay for the product
Step 2 is where you will choose how you want to receive your refund
Step 3 is where you will actually transmit your return

As long as you do not complete Step 3 your return will not be submitted.

After you file

You can lock in the current fee, which TurboTax likes to raise in March.
You can preview your entire return for correctness, which is important.