Resources-for-Beginner-Bug-Bounty-Hunters

Labs & Testing Environments

Hacker101 | Good Exercises for Beginners, can earn you private Invites on HackerOne
Pentesterlab | Good Labs with a broad variety of Topics, some very good Web Application Exercises
HackTheBox | provides Testing Labs, some Web Application Challenges
XSS-Game | Learning Platform for XSS
HackEdu
DWVA
Google Gruyere
Web Security Academy by PortSwigger
XSS Labs from PwnFunction Great Labs in a beautiful layout