First & foremost important thing to learn in networking is How a computer connects to another computer on the network.
Understanding TCP/IP addressing and subnetting basics
if you wish go little bit deep down then you probably wish to learn how a computer gets an IP address and what are the protocols work behind the scene.
An IP address uniquely identifies a device on a network. You’ve seen these addresses before; they look something like 192.168.1.34.
An IP address is always a set of four numbers like that. Each number can range from 0 to 255. So, the full IP addressing range goes from 0.0.0.0 to 255.255.255.255.
The reason each number can only reach up to 255 is that each of the numbers is really an eight digit binary number (sometimes called an octet). In an octet, the number zero would be 00000000, while the number 255 would be 11111111, the maximum number the octet can reach. That IP address we mentioned before (192.168.1.34) in binary would look like this: 11000000.10101000.00000001.00100010.
DHCP defined and how it works
DHCP stands for dynamic host configuration protocol and is a network protocol used on IP networks where a DHCP server automatically assigns an IP address and other information to each host on the network so they can communicate efficiently with other endpoints. Read more in