What are the kinds of things you can do to avoid hypogonadism?

Healthy lifestyle: Some cases of hypogonadism are genetic/metabolic or due to definite acquired cause, but generally speaking unhealthy lifestyle can accelerate process of hypogonadism.

Different in kids: In pediatrics hypogonadism is not a matter of lifestyle intervention. Children presenting with hypogonadism can be born with it or it can be acquired as a result of gonadal injury from trauma or forms of chemotherapy/radiation. However, we see kids with delayed puberty who are not necessarily hypogonadal, but "late bloomers." a doctor would need to determine this.

Sleep Deprivation: Besides aging, the two most common causes i see of secondary hypogonadism are sleep deprivation and vegetarianism. So, get a good night's sleep and eat meat.