Becoming a Webmaster is no longer a rocket science and there are no formal or strict needed things to become a webmaster, but you'll need skill in certain web-based skills like programming, site layout, content development and server management skills to succeed.
Webmaster Basic Level:
At the basic level, you need to learn the combination of these:
1. HTML5,
2. CSS3.
3. CPanel/WHM,
4. Web Hosting,
Webmaster Advanced Level:
At the advanced level, you need to learn these:
1. JS,
2. PHP or ASP
3. Cpanel,
4. WHM,
5. Web Hosting on Shared Server and VPS Servers
Webmaster Professional Level:
At this level you should have passed through basic and advanced level, and will be looking at learning:
1. (solid basic structures on which bigger things can be built) (React, Laravel, or Django/Python)
2. Cloud Server Management (Digital Ocean)
3. Moving (from one place to another) and (finding the source of problems)
4. CDN and Uptime Management (CloudFlare)
5. Speed and Load Balancing..