You can be called to something and still need to learn it step by step. Calling doesn’t skip the training.

A strong pull toward something is not the same as being able to do it. The conviction tells you the direction; it does not supply the skill, and expecting it to is how people quit. Everybody good at anything went through a stretch of being bad at it in public. Being meant for something is not a reason to skip the years.

Pick the next concrete skill rather than the whole vision. Join the thing, take the beginner slot, let somebody experienced correct you this month. Count the lessons as part of the calling and not as evidence against it.