IPad 1 any way it can update.

If you mean update your iPad to iOS 10, there are two ways for you: update over the air or with iTunes. Here is a detailed post:
How to Install iOS 10 on iPhone iPad

The apple store is great help in this area. Apple is a little complicated. Their Tech's are very helpful.

Hagd!

Sorry iOS 5.1.1 is the final for the first get iPad. Time to get a more modern version.

Unfortunately, Candy Crush is no longer supported on the iPad 1. This link will take you to a supported devices listing. It is calling for the iPad 2 or newer.
Candy Crush Saga Faq Mobile en King

Oops,
Heidi, again.

My excuses you already did put the most important things here.
Right. The first iPad, only can install iOS 5.1.1 If you go to settings, general and then to the second line Software update, it says (should say) iOS 5.1.1 software is up to date.

And yes. Lots of apps now on the market, are written for the newer iOS's Latest version is iOS 8.0.2.
But these iOS's and modern Apps, need fast processors and a huge memory.
Apple now has the A8 processor, must be the eight generation of processor and the memory where the programs (apps) are running in, now are 4 times as big as in 2010, when the iPad 1 came on the market.
I still see lots of people use the iPad 1 and as long as they don't want newer apps it is still a great machine.
If you really want to run the new apps, you better wait a few weeks, because Apple will announce the new iPads soon.
Even if you don't want the newest, the other versions will become a little cheaper, as soon as the new iPad(s) are on the market.
Dont buy a iPad 2 any non retina, because they will be in the same situation (not possible to upgrade) soon.

Be aware, Apple is bringing new iOS's almost every year, and the devices, still powerful enough can upgrade without any problem. There is no Android firm, who delivers major updates for their older devices. If you want to update, you must root the device first and then you can install other operating systems, with the risk the device never works as it used to be. For this you should have lots of knowledge about computers and work through lots of frustration, if it does not work the first time you install a rooted android version. And there also is a limitation. When the processors become faster and the memory increases, the older devices can't use the newer rooted versions either.

Ipad 1 / 3g is limited to iOS 5.11 only. No idea if Ipad 2 can go up to iOS 8. Upgrading a older model with a newer software isn't really going to be smooth.

if you have laptop/desktop computer you can sync the iPad with iTunes and download iOS 8.1.2 there:
Upgrading iPad to iOS 8: Through iTunes 1. Backup your iPad
Open iTunes. Select your iPad in iTunes and click Back Up Now.
2. Restart your iPad and your Computer
3. Download and Install the Update
Go to iTunes -> Select iPad -> Check for Update -> Click Download and Update

Whichever method you choose, the process will take quite some time to work depending on how much free storage you have on your iPad, your internet connection, and how Apple's servers are doing with upgrades. Occasionally, Apple will either not let you download the upgrade or it will fail. For iOS 8, you must have an iPad 3 or newer. This does not work with the original iPad - if something goes wrong, restart your device, and try again.

How to Upgrade to iOS 7 on an iPad or iPad Mini
How to Install iOS 8 When Your Device is Low on Storage

Hi, Try refreshing the page F5 key or refresh button on your browser. If that doesn't work you need to update or upgrade your browser.
(old to new) Good luck.

then your iPad is too old for iOS 7-
it works only on iPad 2 and newer


iOS 7 COMPATIBILITY

if you have a first gen. iPad you cannot update to iOS 6 as it is only compatible to iPad2 and newer:
First gen iPad not getting iOS 6 update Apple confirms