My mom's iPad's screen has failed so she asked me to look into a new iPad for her. I'm not generally interested in Apple products personally; in just five minutes of research, I ran into the same confusion you have. iPads used to be simple: there was iPad and iPad Air. One would only buy an Air if one's use case was basic apps without a lot of hardware requirements (e.g., for children).

My mom also uses one of those magnetic keyboard attachments; she needs a new one because it's in rough shape. Come to find out some of them are over $300.