How can I back up my ICloud Messages

How do I install IOS 14. AOL says my iPad is too old. ITT won’t allow me to delete anything nor willl it allow me to receive new emails. It states I have 600 emails but won’t show them.

How do I install IOS 14. AOL says my IPad is too old to install. It won’t allow me to delete anything nor will it allow me to receive new emails. It shows I have 600 emails but I can’t locate them