Updating original iPad 1 to iOS 8

The apps simply cannot run on the hardware you have, they need newer versions of iOS, and your device doesn’t have enough power to run the new OS. You simply can‘t without first updating your hardware. If there are things you want to run or need to run and you can’t get them on the device that you currently have because it’s not powerful enough, the only way that you can is to update your hardware.

It's correct. That iPad can't be updated past 5.1.1.

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The only way you can get iOS8+ would be to get a newer device.

As Neil say, you can update no further than iOS 5.1.1. In this case, to run iOS 8-capable apps (or even apps that require iOS 6 at a minimum), you need to purchase a new erdevice...there's no getting around that fact.

The main reason for this is that iOS versions above 5.1.1 (along with newer apps) require more system RAM than the iPad 1 has. The iPad 1 has 256MB of RAM while the iPad 2 has 512MB with RAM, growing to 1GB for other devices and 2GB for the newest iPad Air 2. Other hardware on the iPad 1 is incapable of newer iOS features as well. It all boils down to inadequate hardware.

how do i update my ipad 1 to ios 8.0 ?

How can i download apps if it keep telling me to update and you say i cant.

The previous replies still apply i.e. you can't