Hey Sue -- Are you sending emails using a free domain like gmail, yahoo, or hotmail? If that would be the case, then it would likely go to spam folders as it uses its reputation to send emails. I highly suggest that you get your own domain to send emails. I stumbled upon this article about using free domains: https://help.convertkit.com/en/articles/2502505-why-do-i-need-my-own-domain-to-send-email6
I also tried reaching out to my subscribers and requested that they allow-list my sending email address so that their inbox provider will not block my email.
The best way is to reach out to ConvertKit's support so that they can check your sending email address if there's anything that needs to be done. You can reach them out here: https://convertkit.com/support5