1. While the sun’s rays can age and harm our skin, they also give us beneficial Vitamin D. 是复合句，while引导让步状语从句。

2. S V and S V是并列句，S V and V是简单句，V and V是并列谓语。I’m going to write good jokes and become a good comedian.是简单句，and连接两个并列的不定式短语to write... and (to) become...。

while引导让步状语从句，带有状语从句和名词性从句的一律归为复合句。

I’m going to write good jokes and become a good comedian

两个以上的简单句用并列连词连在一起构成的句子，叫做并列句，其基本结构是“简单句+并列连词+简单句”。本句中and连接的并列谓语，这一句是由and连接的简单句。