Don't enter zeroes in any of the required fields of TurboTax. Leave the spaces blank for the time that you didn't have your Marketplace Health Insurance or where there are zeroes.
To return to the entry screens to edit your entries, refer to the TurboTax Help article Where do I enter my 1095-A? for navigation instructions.
Despite it saying 0.00 for January and February for A., B., and C. do I use healthcare.gov tool to find what the actual correct number suppose to be?
No.
You only use the Healthcare.gov tax tool to calculate box B (for the second lowest cost silver plan) when box B is blank or shows 0 for any month you or someone in your household had a Marketplace health plan.
For any month you did not have a Marketplace plan, just leave boxes A, B and C blank.