You want to now rape their accounts after finding shit, H4xx1ngbasically it cracks passwords and finds re-used stuff, good to allow you to access the account of a OPSEC demon
https://hashes.com/en/decrypt/hash - Used to crack password hashes and help with finding accounts linked by a re-used password. You can pay them with crypto to crack the hash and refund if it isn't found after 6 hours
https://hashmob.net/ - Basically the same as above but requires registration.
https://hashcat.net/hashcat/ - Hashcat is a hash cracker for more technical users and you don't have to pay anybody. It utilizes your CPU or GPU to guess up to Ϫ Billion passwords a second (depending on your specs). Might be slow or hard to learn if the password isn't shit, or if the hashing algorithm is good.
https://www.openwall.com/john/ - John the Ripper is another hash cracking tool also ran on your own computer. It is good for people without a GPU and is easier to learn. It's best to use both John The Ripper and Hashcat because teamwork makes the dreamwork.
https://weakpass.com/ - Wordlists for hash cracking, there is also a hash search with no captcha
https://crackstation.net/ - Oldfag hash search that barely works
Other:
https://cheatsheetseries.owasp.org/index.html - Series of cheat sheets explaining common exploit types
https://www.kali.org/ - Debian based Linux distro with many hacking/penetration tools used by professionals, skids, and jeets alike. Best to use this in a virtual machine.