I heard from someone that if you want to earn money without any investment then you should go to bitcointalk. But he also told me to keep alert. I created an account. I am feeling very confused but I am not able to understand anything.
To make money without having to spend money on bitcointalk, the easiest way is to follow a paid campaign like most people do, but especially payments using bitcoin will be a little more difficult because usually the campaign manager will see the quality of your posts, merits and activity on the forum. It is still very new for you to know this and you should focus first on learning to understand the forum so that it will be easier for you to reach your goal.
If this is a suggestion from your friend, then learn from him and most importantly do not make mistakes that are not allowed by the forum. Don't be greedy and continue to increase your knowledge first so that it will be much easier for you to achieve what you want.