When user earn on Zareklamy, the entire earned amount is already calculated with tax - net. The tax is only borne by the user paying in a currency other than USD. Read more about receiving transfers.
You do not need. This is an additional job – you cannot retire from it, so you do not pay any taxes. You earn the entire amount without additional commissions.
Do not worry. You can earn money, but it have to be withdrawed by one of your parents because you do not have a bank account yet. If you really have your bank account, you can then earn money. If you are under 18, we recommend using Zareklamy with the help of a parent.