Penetration Testing

FreeCodeCamp has provided this playlist for people interested in beginning with penetration testing.

PortSwigger is a good place to learn about vulnerabilities. You will find vulnerability based testing here and look up specific things on google or youtube to learn them.

For bug bounty hunting, you can visit bugcrowd hackerone and tryhackme. Use WPScan to know about vulnerabilities affecting wordpress installations and plugins. Useful in ethical hacking. Google Hacking Database is an index of search queries which can be used to find publicly available information, intended for penetrators and seurity researchers.