is my iphone 6s jailbroken?

If you are not sure it is jailbroken, then I would suggest that you perform the steps to restore it regardless.

Some methods to determine if it was are:

• Check to see if the Cydia app is installed on the phone.
• Check for phone modifications. That is features that are not native to the iPhone.

You can find numerous articles on the Internet on how to restore a jailbroken phone, but the following will be the basic steps needed:

1. First verify that you Mac or PC is running the latest version of iTunes. Note that iTunes is no longer available on Macs after macOS Catalina. In this case, you would use the Finder app.
2. Connect your phone to your Mac or PC using a Lightning-to-USB cable.
3. iTunes (or Finder) should now detect your phone. If not, you will have to use DFU mode to restore it.
4. In iTunes, select Summary > Restore. Note that if you had been backing up this phone, while jailbroken, you will NOT want to restore the data from a backup.
5. If all goes well, you should be greeted with the Apple logo, and then, the process to Activate the phone.

You could entirely wipe the phone. (Settings-general-reset-erase all content and settings)

And is this phone newer than their phones you’ve had? Because is so, they could just be features that your last phones didn’t have.

Giving you any advice about how to use a jailbroken iPhone safely is a violation of the terms of use of this forum. If you didn't jailbreak your phone, it's likely not jailbroken. They don't jailbreak themselves. If you choose to jailbreak your phone and you brick it, which is quite common, you won't get any support here or from Apple at all.

If you jailbreak it, you completely eliminate the built in security of the device, not to mention forfeit all rights to support.

You can't get help here or from Apple for a jailbroken phone.

I would recommend erasing all content (shown above) just to be safe. And the iPhone XR is a wonderful phone. And iOS 14 is also great!