Where do I find the Pensions and Annuities Worksheet? I cannot access any of the tax forms on the online turbo tax version I'm using. I need to edit it.

Only TurboTax Desktop programs allow you to edit directly on Forms. 

Where and why are you being asked for this worksheet?  The worksheet name is not available in the TurboTax program.

Are you entering a 1099R?  What do you need to edit about it?  It usually fixes it if you delete the 1099R and enter it again Manually, especially if you imported it.  

Edit a 1099R under
Federal Taxes
Wages & Income
Then scroll way down to Retirement Plans and Social Security
Then IRA, 401(k), Pension Plan Withdrawals (1099-R)