I need three tax form because I have 3 different taxes to prepare

TurboTax does not send you tax forms.  The TurboTax program is do-it-yourself software to assist in completing and filing your federal and state tax returns. 

The TurboTax online editions are for completing one tax return per account and User ID.  If you need to complete another tax return using the online editions you would need to create a new account with a new User ID - https://turbotax.intuit.com/personal-taxes/online/

You can have up to 5 User ID's associated with one email address.

Just to make sure---do you need to prepare tax returns for three different people?  If you have to do returns for different people then they each need their own account, or you should be using desktop software which would be more cost effective for multiple tax returns.  

But if you are confused and have three W-2's or tax documents for yourself only, then they all go on the SAME tax return.  All of your own income goes on one tax Form 1040.

What are you trying to do?