Venmo did not give me a 1099-k this year, how do I file my monthly statements and what do I label them as?

If the Venmo payments you received are income for your Schedule C self-employed business, just enter the total income under the 'cash' category.  

Be sure to keep your own records showing the amounts you received and how you determined your total cash income for the business.  Since you did not receive a Form 1099-K, do not enter the income as if you did get that form.