in order to see and save your private keys. you will need to use a desktop computer. Then get the Hive Keychain extension (in Chrome/Brave or Firefox browser). After the Hive Keychain is installed, then you can input that master password that Esteem gave you. Then you go into the Hive Keychain, click on the hamburger menu (3 horizontal lines) in upper right corner, and click on "manage accounts". You should see your private keys there.
I have advised the Esteem team to make the private keys accessible within the Esteem app, so this process is easier, and they said they are already working on this.
I agree that this part is rather complex....
All these links that i mentioned (Hive Keychain) are in that first tutorial named HiveNoobs.