Enumeration

Ports

Nmap

This go-to will scan for all software versions, the operating system version, and check ports for UDP.

$ nmap -A -Pn -sU -T4 target.com

Hidden Files & Directories

Gobuster

There are lots of places that you can get lists to use with this one, including SecLists, but I prefer the standard dir lists here.

$ gobuster dir -u http://target.com -w /usr/share/wordlists/directory-list-2.3-big.txt -t 50