Sure, the paper wallet is the safest option, but how? For example, suppose I wanted to save a considerable amount of money in bitcoins (in my case I will take the example of R $ 100), so I have to let it all just in this paper wallet?
"Paper wallet" doesn't necessarily mean paper. Paper wallets also include "brain wallets," where you use a password nobody can guess/crack and use that anytime you need to generate the proper address. In this case, only you know the information, and you're not relying on paper. On top of this, you're remembering a password, rather than a long address.