Yes. When I didn't see them in iCloud, I found my old notes in my EMAIL folders of all places!!! Check you emails (any emails that you may have used) and see if you can find a folder called NOTES. I couldn't believe my notes were scattered between three different e-mail accounts. If you go to SETTINGS, then Mail, contacts and calenders---check which email addresses are listed, and if any are turned ON, turn them off, then your notes won't be synced to your e-mails and will instead will go to ICloud if you have Icloud set up. Check it out, worked for me. Good luck!
Yes, if you have an iTunes or iCloud backup for your iPhone, you may following this guide to get back your notes from it.
iOS: How to back up and restore your content
Or, you will use a third iPhone recovery software to recover your notes like this blog's instruction.