Basically, for doing Proof of Stake needs to install QT-Wallet to run full node of that coin. And running 24/7 and will keep block record on your device. You need to use more storage on your Pi, add a fan to keep your Pi cooled. And else:
Your wallet needs to be synchronized with the blockchain.
You need to put some coins in your wallet.
The coins must have matured.
Thanks very much for your answer. Do you know if this is simple to install and configure ? I had a look and some people got some issue.