If your ETH is in your personal wallet that you have securely hold your private and account information, no need to do anything as the update of a better ethereum blockchain will just take effect with your wallet intact. Also, stakes for ETCV and ETN for every ETH you have requires your ETH in your personal wallet to receive it. The Constantinople hardfork, on the other hand, allows you to even hold on some specific exchange like Kucoin, Binance.