In lead climbing you have the added difficulty of clipping your rope, managing a rope from below and not above, and the potential for more fall energy. To help transition from top rope climbing to lead climbing you can use a technique called mock lead. You tie in to the top rope as usual but you also tie in a lead rope. As you climbing under top rope protection of the top rope, you climb as though you’re on lead.
This practice helps build stamina and planning strategies so you can lessen the learning curve of transitioning to lead climbing. Be advised however that you should always do a safety check with your partner and take note of the knots for each rope and the protection and the practice.