Jhonatan Peter You can see the different plans here: https://www.bunq.com/benefits
The Easy Savings plan is completely free. But it is only a savings account. You can put your money there, as much as you want. There are only fees if you have a balance over 1.000.000 Euro (more info: https://together.bunq.com/d/44050). As long as you have less than 1 million Euro on your account, there are no fees.
If you want full banking functionality (like bank transfers, direct debits, cards etc.), then you need a paid plan. But if you just want a savings account, then the free Easy Savings plan is enough.