Hi, what is the best way to store Ethereum safe and what wallet should be used?
When you talk of safety of your coins, you want to consider having access to the private key which is considered as the master key to override any application passwords.
MeW like @Findingnemo said is a good start but several wallets today give you that access to your keys like a dex for example idex,forkdelta (**not a wallet but they do generate them**) and many others. Generally just find a wallet that will give you access to your private keys.
What is more secure to store all Eth in one single wallet or use more wallets? Thanks.
My rule of thumb, always spread your risk...you don't want to find yourself in a situation where you lose access to your wallet and you lose all your assets like killing two birds with one stone! My answer to this would be use several wallets!