Personal loan interest ... where do I enter this?

 

Deductions & credits

personal loan interest is not deductible for federal income tax purposes.  maybe state but that would be through the state interview. 

Deductions & credits

However, you may be able to take a tax deduction if you use the loan for certain, specific purposes and meet all the eligibility requirements. "Business expenses", "Qualified higher education expenses", "Taxable investments"