Many user have answered your question very well, so no need for me to answer it again
Your account is very suspicious for me, Looks like hacked or changed hand account
How do i join the bounty? Where can i find? What should I do while joining the bounties?

Today you're asking how to join bounties, but on 2 years ago you can join a bounty and reporting your post (literally you know how to join,participate, and complete the task)