Like most have said, just start.
Gary Vee, love him or hate him, has it right in getting people to be confident in their ideas rather than wait for "the perfect time."
Whichever route you take, it will be difficult in the beginning. I work in sales, and a lot of us "found" ourselves in this profession. Very few people grow up saying, "My dream is to be a salesperson!" And we suffer more than we have to because we are in the business unprepared.
Sales is a form of entrepreneurship, one among many, and the most important thing you can do is be very clear on your values and your goals first. This will give you a firm foundation where you will be less likely to fold or concede under pressure, and will give you a backbone and identity which will draw people to you as a leader.
You might find this helpful: http://www.negotiations.ninja/podcast/negotiate-like-an-entrepreneur-with-marty-park-ep117/
All the best, M