Hey Anwar, thanks for getting in touch!
Absolutely. You can use Event Tickets and Event Tickets Plus with or without The Events Calendar. Event Tickets works on its own but has that nice integration with The Events Calendar, should you need it. 🙂
We don’t have trials, but we do offer a full refund on all products within 30 days of purchase. That should give you a fair amount of time to see if you enjoy the plugins and to return them if they don’t work out for any reason.
Does this help answer your questions? Please let me know. 🙂
Cheers,
Geoff