You can download Windows 10 from official Microsoft site by following method :-
1. Go to this link -https://www.microsoft.com/en-us/software-download/windows10
2. You will get 4 OS Edition available to download, don't pay attention to Windows 10 KN and Windows 10 K because they are specially made for Korean and European countries. You will miss some features such as Media Player in these variants. So, Just go for Windows 10 and Windows 10 Single Language. If you want to go on my behalf then you must go for Windows 10 because it will have all the languages and will only differ with the size of around 100 MB.
3. Click the version, choose the languages and click confirm.
4. Next page will show you 2 option 32 bit and 64 bit, download whichever suits you best. If you have RAM of 1 GB then go for 32 bit, If it is more than 2 GB RAM then 64 bit will suit you best.
5. After clicking your version it will start downloading.
As Muddassir told the download link will expire in 24 hours.
You won't be able to do these on any Windows machine because they are made to update only. Either you go for any Mac machine to download Windows or use 'User-Agent Switcher' which will help you to fool the site and make them believe that its Mac.
By the way you are making an awesome decision by Windows 10. You will get many new updates and best one is Edge Browser.
To get Microsoft Edge Browser Review - Microsoft Edge Review
Get a glance of new Windows 10 features - Windows 10 - Best Windows Ever?