I think it is very easy to join the bounty, you simply choose a bounty tread that you will follow then you just read the requirements. remember, there will be a lot of bounty and try to choose a good and successful.
It is easy if you are a experience bitcoiners since he was a newbie that's why he's asking for a advice,there is many ways to participate signature and bounty campaign since you are a newbie you need to research and study the furom and familiarize the history of crypto currency,and if you participate bounty campaign read the rules properly and follow it remember spamming is not allowed and before you participating a ICO read there white paper,roadmap and choose a successfuly project with trusted team.