I need to download the iOS 10.0 on my iPad 2 Apple please i can not do any downloading

be sure to check your available memory AND be sure your ipad is PLUGGED IN to the electricity to continue full download (this is a must)

It may be too full. Check how much free space you have. Try to have approximately 3GB free. Delete things that are easy to replace like apps, or music you can download again.

Yes!
Most people are now on iOS 8.4
So.... do you mean back grade? from 8 to 7
iOS 9 will be released in a few days!
https://www.apple.com/ios/

It can be downloaded & installed directly to your iPhone/iPad
Or... as I prefer.....
use my computer running iTunes to firstly Backup the iDevice (using it's USB charge cable)
ITUNES will at this time indicate that there is an update available for your iPad.
Choose to "download only" the new iOS.
If you have other things to do!
Disconnect while the download takes it's time downloading.
Then come back later and plug in USB cable and "Install" the updated iOS.
How to Update iOS Software on an iPad

Even when you manage to put the Google play store app on your iPad, you won't be able to run any of the apps they sell there. You need an android tablet to run these apps.

Unfortunately you can only update to 5.1.1 for the ipad1

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

install netflix on ipad first gen.:
first make sure your iPad 1st. gen is on iOS 5.1.1 !
It is possible, a bit tricky, but possible. First, you'll need to download the Netflix app through iTunes on your computer, this will make it show up as "purchased" in your library. After that, open up the App Store on your iPad 1 and go to the 'purchased' tab. When you try to install it this way it will tell you that you need iOS 6 or higher, but will also ask if you would like to download an older version of the app. then click on download.
- again step by step:
1) Open up iTunes on your computer
2) Go to Store (left hand column) ->iTunes Store
3) Search for Netflix; - download the app
4) then open App Store on your iPad
5) Click on 'Purchased'
- you will have to install NetFlix by clicking on it as usual.
App Store will ask you: "Download an older version of this app. The current version requires iOS 6.0 or later, but you can download the last compatible version.",
then click on Download and it should finally work.

The latest version of iOS today is the iOS 7. And iOS 7 is supported by your tablet (Apple iPad 2 Wifi16gb). So it is much better if you will download the latest version for fuller productivity of your tablet.

iOS cannot be downloaded with safari
There are two ways to update the iOS version of your iPad 2:
- via connecting the device to iTunes on a computer
- or directly from within the device
but only since iOS 5 it is possible to update the iOS version without the need to connect the iOS device to a computer (over-the-air update)
just go to: settings - general - software update

the first gen. iPad is not compatible with iOS 6
- you need a newer one....
Apple iOS 6 Finally Available for Download Direct Download Link Download Apple iOS 6