where is recommended to keep coins safe and get some incomes/profits from them?
It might be what you mean is staking coins and there's no wallet that has a feature, except the exchange but first, researches it first which exchange is the best to entrust your fund. This is the tougher choice that you need to have research first and don't rely on any financial advice.
Exchange servers or on cold/warm wallets?
They are totally different, for safety and holding for the long term, non-custodial wallet or hardware wallets is the best choice.
Remember always as our golden rule, "
Not your keys, not your coins"
and which Exchange server is your preferred? Kucoin or Binance?
If you're not afraid of KYC and you're willing to give your personal documents to them, Binance is good to entrust your fund as a third party who holds your fund, as the feature they have (SAFU) which is the promised a secure fund of users, it might be they are a good choice since they are reputable, Kucoin doesn't have this but they don't have KYC as their minimum limit.
It's your call now which you prefer, DYOR is always in every decision you plan to make.