If you are not a W-2 employee of the real estate firm, then you are a sole proprietor/independent contractor that would report their income and expenses on a Schedule C. You can enter your expenses without having any income on the Schedule C.
To complete a Schedule C using the TurboTax online editions you will need to upgrade to the Premium edition.
See this TurboTax support FAQ for Schedule C - https://ttlc.intuit.com/turbotax-support/en-us/help-article/import-export-data-files/enter-schedule-...
