I am not sure whether you are too young or the other way. I would say there is not much requirement on "age" for a career in networking particularly. If you have concern whether it is "too late" for you to enter into a new industry, I would say if you are interested on networking, it will never be "too late" as I have people around me from all age groups. Of course, most of people have completed their high school and some sort of university study which means they are 18 years or older.
To get into a decent career you would need a minimum qualification of a graduate degree.
Any networking job would require the same. To start off a career in networking the widely accepted certification is CCNA (Cisco Certified Network Associate).
All the best !
Entry level human resources jobs are usually looking for employees with some experience and at minimum a high school diploma and bachelors degree in Human Resources or a related field. Larger companies often offer robust internships that can lead to a full time role. That's how I started out!
You'd most likely need to be over 18 and between 20-24 for a entry level role in Human Resources.
Jeffrey recommends the following next steps: