For me I recommend Blue Wallet just like Charles saidin the first comment, it's important that we take close considering on some factors when we are making decisions as far as wallet is concerned which are features and security, and for that we got that all in Blue Wallet, I know there are other wallets, but for me for less complexity, chose blue Wallet.
When you talk about security, both wallets mentioned are always among the best recommended since they are both open source, and I give both the same rating, but which one a user should choose is based on what device the person is using.
Electrum only works on Android devices; it doesn't support iOS, which is where Blue Wallet provides more options to both users (but since it's a mobile/hot wallet, there are still some dangers associated with it; only a few coins are recommended to be stored on it for security reasons since the device can always have an internet connection).