Hey there, Arebhy Sridaran
When you register for digital events, you should get an email from the events team that tells you if you have registered for the event and when it is. You should have the option to add the event to your Outlook Calendar.
If you have added it to the Calendar, please click onto the event and you should have a link to join the event or have a link in the description body to join the meeting.
If this is what you, but still found it difficult to join, please reach out to the event team who organised the event. Most of the time, the meetings are recorded so they should be able to hand you the recording for the event.
As you have missed one session, it would be best to reach out to the events team who organised the event. They can let you know what they can do from their end. The event is here: https://techcommunity.microsoft.com/event/partnereventscalendar/microsoft-azure-virtual-training-day-fundamentals-day-1/3984359
Hope this information helps,
Nathan