You can try the Blockchain wallet it's a multi-coin wallet,(open source), and also Coinomi is a good candidate But if you are using multiple gadgets like Desktop, laptop, and smartphone (Android and IOS) I can also recommend the non-custodial wallets like Atomic Wallet, Imtoken, Trust wallet most of it are supporting many coins that's why it is worth to use. for the cold wallet I think the top names are Ledger and Trezor just choose any one of it.
Coinomi today also support Desktop/laptop (Windows, Mac OS and Linux) and Smartphone (Android and iOS).
And which can I also use for exchange between currencys?
Local exchange on your country is most ideal option, especially if you need to deposit/withdraw to your local bank account. Otherwise, Binance is good option unless you have very specific needs.