I started my tax return and I did not change my marital status, but I want to change to head of household. The program won't go back to the beginning to allow this?

You do not mention whether you are legally married or if so whether you have lived with your spouse for the last six months of 2023.   Filing status ---single, married, head of household---is entered in My Info.  You can go to My Info, click your name and make a change.   However----do you qualify to file as Head of Household?   That filing status will be offered to you if you meet the criteria.

 

Am I Head of Household?

https://ttlc.intuit.com/questions/1894553-do-i-qualify-for-head-of-household

https://ttlc.intuit.com/questions/2900097-what-is-a-qualifying-person-for-head-of-household

 

If you qualify as Head of Household, when you enter your marital status (single or married filing separately) into MyInfo, and then enter your qualifying dependent, TurboTax will offer HOH as your filing status.

In the MY INFO section you need to edit yourself and answer the MARITAL status question and then after you enter a qualifying person as a defendent in that section the HOH filing status will be presented if you qualify ... you cannot simply choose the HOH filing status yourself.