Unable to transfer Notes from MacBook Air to iCloud

Check you iCloud storage is in designated purchased limits , make sure notes box turned as on .

May be you are using third party apps / softwares ( if so uninstall them , create a new admin account New user or group setup on Mac - Apple Support in users and groups and configure notes Set up iCloud for Notes on all your devices - Apple Support

See the article Change settings in Notes on Mac – Apple Support

Enable the On My Mac account

Store notes on your computer using the On My Mac account.

Another article About accounts and folders in Notes on Mac - Apple Support 

• You can only move or copy locked notes between folders in your iCloud and On My Mac accounts (and you may need to unlock them to do so).

Also , if notes are in on my Mac section , you can select the notes data from individual note , copy and paste in new folder created in iCloud section , use Mac keyboard short cuts to select , copy and paste items Mac keyboard shortcuts - Apple Support