Am I able to do my personal taxes with a small business started at end of 2019 on the app?

[LeonardS]

Yes, you can prepare your personal return and a small business return Schedule C Profit or Loss from Business using TurboTax Premier online or the download version.

[VolvoGirl]

Depends what kind of business you have.  If you are self employed or sole proprietor or a  single member LLC it would be reported on Schedule C in your personal return unless the LLC elected to be treated as an S corp or C corp.  In the Online versions you can enter self employment income in Deluxe or Premier but if you have any expenses you will need to use the Self Employed version.   Or you can use any of the Desktop installed programs.  All the Desktop programs have the same forms.

If you need to do a separate Business return for a 1120 Corporation, 1120S Corp, 1065 Partnership or 1041 Estate/Trust return you need to buy Turbo Tax Business in addition to a personal  program.  

Turbo Tax Business is not available to do online or on a Mac. You can buy the Window's (Win 7 or newer) version here. And you can have both TT Business and TT Home & Business (or any personal version) installed on your computer at the same time.
https://turbotax.intuit.com/small-business-taxes