Getting into ethical hacking as a beginner, one has confusion about where to start. There are many resources but the only question remains in mind for a beginner is "What is the zero level to start?". But, here are some tips for you if you want to get started.
Get knowledge on,
Networking:
- OSI, TCP/IP models
- TCP/UDP Differences and Flags
- Three-way handshake(SYN, SYN&ACK, ACK)
- Ports and IP, how it works
- Mostly used port numbers
- Public and Private addresses
- Definitions of DHCP, ARP and how they work
- Subnetting(Just introduction is excellent)
Cryptography:
- Descriptions of Symmetric and Asymmetric encryptions
- What is Public key and Private key
- Hash and Encryption difference
- HTTPS and why to use SSL/TLS
Programming:
- "Eeew not C" go for basics of python. Programming is not compulsory, But always preferable.
Other:
- Get familiar with basic Linux commands.
- Using Putty or SSH
- How Server/Client works in networking model.
- How HTTP protocol works
Again, it is always prefered to know these domains, no need to be an expert. Always remember, Practice while you learn. Learn while you practice.