While it's not exactly 2FA, some versions of Android (including AOSP builds and the official stock ROM's on Google's Nexus and Pixel phones) support multiple users. If you're just looking to keep people who are borrowing your phone from messing with your applications, this should be enough to get what you want. In particular:
- Each user has their own apps and their own storage directory. New users start with an empty storage directory and whatever stock apps your phone came with.
- Each user has their own password, and if the device is encrypted using the newer file-based encryption (used in 7.0 and newer by default), each user's files are encrypted separately.
- Switching users drops you on the lock screen, and you have to unlock the device using the target user's unlock method (password, PIN, pattern, whatever else).
- There's a specific distinction between admin users and regular users. Only admin users can create new users (except see below about the Guest account) or change certain device-wide settings.
- Certain things are functionally available to all users. Any user can initiate application updates through the Play Store, which will update everybody's applications. Wi-Fi configuration is shared too, as well as a number of other configuration options that are device-wide but directly affect the usability of the phone (though Bluetooth associations aren't).
- The phone number will not change when you switch users because it's tied to the SIM card. This means in particular that any user can initiate calls or send texts using that number (except see below about the Guest account).
In addition to all of this, there's also an ephemeral Guest account. This account has some special handling around it, namely that anybody can switch to it, it's not password protected, you can turn off the ability for it to make calls and send texts, and that it is completely reset whenever you switch to a different user (IOW, when you switch to another user, the Guest account gets wiped).
On stock builds of Android 8.0 (more specifically, on phones running 8.0 that don't use a custom settings app like Samsung phones do), you can find configuration options for adding new users in the 'Users & Accounts' section of the settings app by clicking on the 'Users' button at the top.