It’s easier to prove your abilities if it’s not the first time you’ll be out there traveling by yourself. Have you ever done anything brave completely on your own, such as moving to a new town where you didn’t know anyone, studying abroad, or a taking trip by yourself? Point to those past successes as proof that you’re capable of doing it again.
If you never have done something like that, then take a baby trip first. It doesn’t have to be anything big. It can just be a long weekend away in a new city. Navigate it on your own, start conversations with strangers, or eat a meal by yourself. It’s a great way to build up your experience and confidence, and also the confidence of those in your inner circle.