fear of the unknown is natural. whether we go where we have not gone before physically, spiritually, or mentally we are taken outside our comfort zone
it takes time to get familiar and confident in new things whether it be a new job, new marriage or something else we have not experienced before.
When I feel afraid I go to God. The Bible says to cast all our cares upon him for he cares for me. For Joshua God told him serveral times to have courage and to not be afraid.
Couage is the wherewithall we have to use to lead others. If we are overcome by our aprehensions then others we are trying to lead will not follow because we will be seen as weak and indecisive.