Hello! My name is Tiana, I am from a countryside of Serbia and looking for a ways to earn some extra money. A friend from Facebook said me that he earns money online through this forum. I was reading this https://bitcointalk.org/index.php?topic=1689727.0 but here there is no any suggest from what to start 
So, any recommendations, guys?
So, any recommendations, guys?You're going to have a hard time if your only reason to join this forum was to make money.
Your best bet would be to sell a certain skill ( programming ) that you have in the service section, https://bitcointalk.org/index.php?board=52.0
Other then that, you could join an altcoin bounty campaign, but that's something i personally wouldn't do.
Or, you could claim bitcoins from faucets, https://bitcointalk.org/index.php?board=212.0 , depending on how you value your time this could or couldn't be worth it for you.