For storage, definitely use a hardware wallet such as Ledger or Trezor. Most people say dont leave coins on exchanges for storage. I guess the exception might be for short term storage if you are planning to sell or trade.
I think cold wallets are always the best option for investors when keeping assets in this market. I have been using Ledger Nano S for the past 3 years and actually it makes me feel safer because the security level of this wallet is very high. In addition, if you transaction regularly, you can choose Trust Wallet, Coinbase, Blockchain because these 3 wallets are also very good for investors.