How To Pick And Work On A Microproject

I have gone through this link
https://git.github.io/General-Microproject-Information/  and I am not
really clear with it especially this line
"Select a microproject and check that it has not yet been taken or
discussed by searching the mailing list. Public Inbox is your friend."
 On the mailing list I see messages with the [PATCH] keyword in front
of them, am I expected to pick one and reply to it? How do I reply
directly under the thread which contains the issue? Please, how do I
find the issue on the Git repository? I checked the repo and could not
find the "issues" section also .
Please HELP!!! Any explanations would be very much appreciated, as I
would prefer to start working on it as early as possible.
Thank you.