That is also a common question. I get my non-lucrative visa for one year. But then, what?
You have two different options.
The first one is to renew your permit. If you still fulfill the conditions (800% of the IPREM on your bank account, private insurance policy…), the renewal will be possible.
Note that in this case, you will have to prove an amount of money sufficient for two years, not for one as in the initial application. That is because, as the renewal lasts two years and not one, the monetary requirement also doubles.
Second, you can also change the initial authorization into a work permit, as we will see below. And you can change to a work permit to work for a company or to become a self-employed individual.