TwentyFourteen The Events Calendar -Sidebar disappears, need probably new templa

I’m using the Modern Tribe Events Calender running TwentyFourteen

There was already once a topic referring to this, but it couldn’t help me the way I wanted, it would just be a compromise.
The topic linked in there is a bit too complicated for me, as I’m new to WordPress. I’m absolutely willing to try it, if that’s what I should do though!

I still want to maintain the layout from the Standard Event Template, mainly because the other standard templates are wasting too much space, leading to an ugly look. Basically I want to mix the best out of two templates.

I added images to visualize my problem: https://imgur.com/a/c9dkC

Am I right in the assumption that I need to create a new template?
If so: Do I need to create a child theme? And Does anyone know where to find the event manager’s theme? Creating an own template would probably not be that easy I assume? I guess I still have a lot of reading to do.

Nevertheless, thank you for your patience and help.