Hi gohwebmaster,
Thanks for getting in touch. I’m not entirely sure I understand what you said about redirecting. Events Calendar PRO is an add-on for The Events Calendar. It essentially works on top of The Events Calendar- you won’t have a second calendar, just the same one with more features. So you won’t be able to redirect to a calendar showing only your old events, unless you do some customizing.
When you activate Events Calendar PRO, all your original events will remain on your site and working. You should not lose any data or have an disruptions. Does that clear things up for you?
Best,
Leah