Gaining your first bitcoin can be done easily by free methods, it will take some time of course but its also worth it.
I would recommend you to do signature campaigns because they are easy and without risks, they only require you some spare time.
But even though joining signature is not that easy. But yes, it is a free method of getting your first bitcoin.
And you can earn by creating constructive post to the thread you are posting in. And it will also take some time for it.