Hi Kamrul,
Thanks for checking out our plugins!
You will automatically have a page that lists past events. While you can charge fees based on sales for tickets that users have created using Community Events, there is not currently a way to charge users for submitting the event itself. We are working on building out this functionality for the future, and I would recommend casting your vote for this feature request so that you can stay up to date as we make progress!
Using Community Events (which allows users to submit events from the front end of your site), the form is built-in to the plugin. You can require users to be logged in to submit events, but there is not currently a way to let them login via social media accounts. This is something that a third-party plugin may be able to offer (I did a quick search and found this one). This is to login to your site in general though, not a specific login for events.
We do offer full refunds within 30 days of purchase, so feel free to take any of our premium plugins for a test run! Please let me know if you have any other questions.
Thanks,
Jennifer