You only get paid when the student confirms that a lesson has taken place. Make sure that you document each lesson before it takes place, then you can remember your student during the lesson to confirm it right after.
You can receive your money through a bank transfer or via PayPal.
To set your preference and payment information go to My profile → Edit → Payouts.
You can request a cash out at any time here or by clicking on € Financial in the drop-down menu in the upper right corner.
Bank transactions are made every Friday.
You are a freelancer. To declare taxes is your own responsibility according to the requirements of your country.