You would file as Single. However, since you have a dependent child and assume that you are providing over one-half the cost to maintain the home, you should be legible for Head of Household filing status. The TurboTax program will ask a series of questions after you have selected your filing status and have entered the child as a dependent to determine if you are eligible for HOH.
See this TurboTax support FAQ for head of household - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-filing-status/qualify-head-household...
