No, it is not bad to use a resume template. No hiring manager will reject your application for using a resume template to format your resume. Resume templates are created to look professional, meet industry standards, and be easily read by applicant tracking systems (ATS).
However, make sure that you replace all of the content with your own experiences and that you choose a template design that is appropriate for your target industry. A simple black-and-white template is always a safe choice if you’re unsure.