There is one who you can always lead. They always do exactly as you will, and never deviate. It is yourself. How well are you leading?
It may not seem like it but the first step to effectively leading anything is to learn the first person you must lead s yourself. You cannot afford to wait for someone else to pick up the slack. You must lead yourself.
Are you longing for mentor-ship and teaching, but your company hasn't provided it? Lead yourself. Find what you need, make a plan, and go look for it. Ask colleagues for their insights. Find blogs of industry influences. There are even a plethora of books on most topics.
Were you dropped into a team that's performing poorly? Naturally you're not in charge. That shouldn't stop you! A Leader doesn't need a title to wield influence. But to gain influence, you need to know what you are about, and where you are going. Then you need to act in congruence with your duty and with your purpose. You need to lead yourself first. Others can see if you do it well.
What a about a challenge you don't know how to face? First and foremost: Lead yourself. Take a step back, and pretend a close friend is asking how to deal with a similar (the same) problem. What did you tell them? Go and do that! 'Take care of yourself as though you were one for whom you were responsible.'*
You can always lead yourself. And in fact you must! You needed be alone, but you must not wait idly by. Feed yourself. Find a goal and begin to march for it. Build your influence, by leading yourself. Act on the advice you might give a friend. Lead yourself with courage.
*Credit to Devlin Liles for this idea.