A mentor is someone with more experience who helps another person grow. In a sales team, good mentoring is often the difference between someone who gives up in the first months and someone who stays and learns.
Share what worked, and what did not
Stories about your own mistakes help more than stories about success. They show the other person that problems are normal and can be solved.
Listen first
Before giving advice, ask what the person is trying to do and what is getting in the way. Often they already know the answer and need room to say it.
Help them find their own way
What works for you may not work for them. People sell in different ways. A good mentor helps the other person find a way that fits who they are.
Agree on how you work together
Agree how often you meet, how they can reach you and what they want to learn. Thirty minutes every two weeks is a good start.
Both sides learn
Mentors learn too. Explaining something helps you understand it better, and newer people often see things you stopped noticing long ago.