Help with resume

Need help with wording resume bullet points that I have below. Also I need more added ,the resume bullet bellow falls in line with a Sales Trainee job.

Assisted outside Sales Personnel and the Branch Manager with various aspects of Branch operation.

Learning product knowledge in the Gas Industry

Established positive rapport with customers, upsold products and built a loyal clientele.

Analyzed learning needs in the area of selling.

Gained and a knowable class and obtained  certification such as millers