Hey there, Alicia!
First off, thanks for getting in touch! I’m really happy to see you’re checking out The Events Calendar and I hope it’s a great fit for your site. 🙂
Events Calendar PRO will not read existing post categories. Unfortunately, those would need to be re-created as Event Categories if you want them to be the same between Posts and Events.
However, do note that Tags can be used instead and are shared between Posts and Events. In other words, if you use the tag “Party” on a post, it will also be made available to tag an event. That might be one approach to consider.
And, yes, you can schedule events to post at a specific date and time as you can a default Post. You would do that in the Publish settings for the event (screenshot).
Does this help answer your questions? Please let me know.
Cheers!
Geoff