Before downloading your chosen wallet, there are a few things you need to know:

1. Backup your wallet keys:
   When you first start your chosen wallet, you should obtain the wallet key. There are two keys that serve to restore your wallet in case you change devices or if your current device stops functioning. Always back up your keys and store them in a secure location where no one else can access or see them. It's recommended to save them in multiple locations so that if one location is lost or damaged for any reason, you can still recover the keys from another secure location.
2. All wallets are secure, but your device may not be:
   This applies to computers, laptops running Windows, and Android devices. Keep your operating system clean and free from security threats like viruses. Use a good antivirus program (preferably paid) and avoid installing any software or apps on your device. The more software and apps you install, the higher the chance that one of them may pose an invisible threat to your system, which can affect your wallets and potentially lead to loss of funds or theft of your keys.