For Head of Household you must have a qualifying person as a dependent. The TurboTax program will ask you a series of questions, if you file as Single and have a dependent, to determine if you are eligible for Head of Household fling status.
See this TurboTax support FAQ for HOH - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-filing-status/qualify-head-household...
