The number of sunspots varies. Does this change the brightness of the Sun?

The spots are surrounded by hotter regions of the photosphere. The total radiation power will be approximately the same. Therefore, the brightness of the Sun will not change significantly.

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.