Yes, your rent expense should be entered separately. Your income should be entered without adjustments. All your income and expenses are reported as self-employment on Schedule C.
The easiest way to find Schedule C in TurboTax is to use the Search box at the top right side of the TurboTax header. Enter "schedule c", hit Enter, then click on "jump to schedule c". This will take you directly to the start of this section where you can set up your business and enter your income & expenses.
Or go to My Account >> Tools >> Topic Search. Type in "schedule c", click the topic in the list, then click "GO".
Once you have set up your business, look for Rental Expenses under Business Expenses >> Other Common Business Expenses (see screenshot below - click to enlarge). This is where to report your weekly booth rental costs.
[revised 2/15/17 for navigation]