Is there a way to do this within Turbotax since the earnings are from 2020 only, none in 2019?
Since the LLC was not created in 2019 then you have nothing to enter on a 2019 tax return concerning the LLC.
Not for income taxes, but assuming that you are on payroll, the 1st quarter employer forms are due at the end of July.
Payroll tax forms are not part of the TT program ... seek local guidance to see what you need to file in your state. https://www.irs.gov/faqs/small-business-self-employed-other-business/forms-940-941-and-944-employment-taxes/forms-940-941-and-944-employment-taxes