At the beginning, you could try to get direct clients and increase your revenue, so it is not important to control your finances. But, when you have an established business, stable clients and different profiles on freelancing websites, you will need to be registered with the Treasury of your country to get your ID tax number and pay your taxes.
It is also important to know about accounting to determine your income, expenses, and utility in your freelance translation business. Every country has different tax laws and norms, so you will have to reach out to your accountant to be clearer about this.