Tell the interviewer that you are interested in continually improving your sales and customer service skills. Reflect on any formal training you have had over the years, from onboarding with a previous employer to hands-on training or industry coursework, or anything you've learned on the job, from customer service to sales techniques. If you are new to your career, you may have self-trained by watching YouTube channels dedicated to sales techniques, or maybe you've spent time reading books on business, sales, and customer service approaches. Relate anything and everything that applies to you personally.