A generic resume and cover letter are more likely to get lost in the shuffle than ones tailored to the company and position, so take the time to customize them.
Consider your strengths and how they support the business, and put that on your resume. Stand-out resumes are more about accomplishments than job duties.
Job interviews are an art form. They range from casual conversations to intense, multi-step processes with projects or homework to complete. You need to prepare for them.
One option to fix this is to take an online class to learn new skills or improve the ones you have.