What basic abilities should a promoter have?

I think you should first understand what products you can sell. Who needs the products you sell? Can the products you sell meet the requirements of customers?

I suggest that you might as well start from the following aspects:

Learn from customers and competitors with an open mind.

Honest and trustworthy, establish a good personal image.

Studious and thoughtful:

Familiar with product performance and selling points.

Understand the products and prices of competitors.

Identify your sales customers, understand their needs and meet their needs.

Be bold, not afraid of setbacks and failures, and stick to it.

Be familiar with your own products and understand the needs of customers. If your products and services can meet the needs of customers, communication will not be difficult and sales will be carried out smoothly.