Q: iPhone (version 9) Notes where to find in Mac

Hi JCBLondon Madrid,

I see that you have some questions about Notes, and I believe I can help you answer these questions. First, Notes on iOS 9 are vastly different from previous versions of Notes. As such, and as stated in the following article:

Learn more

Here are a few things to keep in mind about upgraded notes in iOS 9 and OS X El Capitan:

• Your upgraded notes on iOS 9 won't stay up to date on your Mac until OS X El Capitan is available.

Upgrade your notes with iOS 9 and OS X El Capitan - Apple Support

https://support.apple.com/en-us/HT204987

So you will want to upgrade your computer to the newest OS, El Capitan, in order to keep your notes up-to-date across your devices. When you do upgrade, your notes will be synced into the Notes app on your computer. 

Your second question is referring to different accounts where you can sync your notes for cloud storage. There is some further documentation about using Notes with these accounts in the following link:

View and edit notes from other accounts (such as Google, Yahoo!, or AOL). Go to Settings > Mail, Contacts, Calendars, then turn on Notes for the account. These notes appear in Notes on all your other iOS devices and Mac computers that are also signed in to that account.

Note: Notes from these accounts can’t use many of the features in upgraded notes.

Turn on an On My iPhone account. Go to Settings > Notes, then turn on On My iPhone. Notes in this account appear only on your iPhone.

 

Use notes in multiple accounts - iPhone

http://help.apple.com/iphone/9/#/iph8f03b43fa

Hope this helps. Take care, and thanks for visiting the Apple Support Communities.