Qualified Business Income

Take what deduction? You can take any expense that you needed to incur for production of income. You need to enter your income on Schedule C and during the interview process, you will be shown typical expenses. 

If you are wanting to find the section within TurboTax where you either enter or have entered your self-employment income and expenses which will be reported on Schedule C of your tax return, do the following steps:

1. After signing into TurboTax, select "Take Me to My Return"
2. Type "Schedule C" in the search field at the top right hand of the screen.
3. Select "Jump To Schedule C" and you will be brought to the section of TurboTax where you can enter or have entered your business income and expense information.

I noticed after I posted the answer, you changed the question to include QBI. Yes, this is potentially available to all self-employed individuals. 

Since you are in a service field, you would need to indicate that. There is an income limitation that few people approach. Again, you will be asked questions in the interview section.