Can you switch to free if you choose Premier at beginning I get SS and part of dead husbands pension gross less than $16K in 2018. So I'm paying $125.00 to file not right

Based on the information you provided, it looks like you may qualify for the Free File Program, which will allow you to file completely for free if you meet certain qualifications. 

For the Free File Program, a user needs to meet only ONE of these qualifications: 

     AGI of $34,000 or less
     or active duty military (including Reservists and National Guard) with a military-issued W-2 and a 2017 AGI of $66,000 or less
     or eligible for the Earned Income Credit (EIC aka EITC).

https://turbotax.intuit.com/taxfreedom/