In FL I rent space in a shop sell items. They handle state sales tax & are reg. bus. I'm not incorp./no EIN. Monthly I get a check gross sales minus rent. Do Iuse schedC?

Yes, you will file a Schedule C as the IRS considers that you are self-employed (a sole proprietor).  The good news is that you will be able to deduct reasonable and customary business expenses from your income. Refer to the article Are Work-Related Devices a Tax Write Off?

Follow the steps below to enter your income and expenses;

1. Open TurboTax
2. Select Wages and income
3. Select Add more income and scroll down to Self-Employment income and expenses and select  Start
4. TurboTax will walk you through a series of questions to report your income and expenses.

Just remember to enter your gross sales (not what was paid to you in your checks since the rent was deducted) and enter your rent as an expense.  For more information, review the TurboTax Help article How do I report income from self-employment?

Refer to the TurboTax articles Beginner's Tax Guide for the Self-Employed,  How to File Federal Income Taxes for Small Businesses and Tax Tips for Sole Proprietors for more information.