First you need to vote for a delegate from your wallet. Then you get rewards just by having a balance in your wallet. There is no need for the wallet to be running all the time.
Ark is DPoS (delegated PoS). This means that only the delegates need to have their nodes running all the time (51 of them with the most votes). The rest just vote.
It's a good idea to check the wallet every now and then. If your delegate stops paying, it's time to change to a new one
Do I choose any delegate or is there a criterion about choosing them?
This might help you
https://arkdelegates.io/delegates/Pick one that "Shares rewards", has a high Payout % and is in the top 51, so he is actually Forging.
Also it's important to know that the higher a delegate is (the more votes it has, 1Ark = 1vote), your vote is worth less. So someone at 40th place with little votes and 80% share is still better that someone at 10th place with 90% share. Here's a nice calculator:
https://arknode.ninja/calculator.phpSo voting for delegates with less votes can be more profitable, but it is riskier because they can drop out (go lower than 51 and stop forging) and you get nothing.
Just pick one in the top 20 that share rewards if you don't check thing very often.
But read about the delegate you choose. Some have minimum wallet requirements... Hope this helps.
