Once you understand binary, picking up Hex and Octal is a walk in the park. Instead of base 2, we have base 16 (hex) and base 8 (octal).
In hex, the characters used are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F.
In octal, they are 0, 1, 2, 3, 4, 5, 6, 7.
Hex is often prefix 0x, octal 0o.