when I copy a page and paste, it copy all the notes I dont need.
How can I do because I dont want to delete one by one all these notes?
If you are directly copying page content (all or some widgets) within the same prototype page-to-page, then the notes get copied over, just like interactions, styling, etc. You can right-click on the page area and choose Paste Special > Paste as image --that will remove the notes, but also interactions, and of course it converts whatever into a plain image.
If you are copying page content from one prototype to another, then you can use the File > Import from RP file… feature. That allows you to choose one, some or all pages, and then later on in the wizard dialog, you can choose to import none, some or all Notes, and even remove the Notes fields altogether.
You can use the Import feature in the same prototype by saving out a copy of your .rp file, then importing pages from that copied file, choosing to remove Notes. That’s probably your best option.