Will we be able to see the planet if it is in the lower conjunction?

Usually not, because in the lower conjunction the planet is turned to the Earth with its unlit side. But if the planet passes along the solar disk, then its dark disk can be seen. Since the planes of the orbits of Mercury and Venus are inclined to the plane of the ecliptic, the passage along the disk of the Sun does not occur very often.

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.