Need Help Setting up Samsung CHG90 Monitor


Dec 18, 2019
Just purchased a new Samsung CHG90 Monitor and need help setting it up.

I do not use this monitor for gaming; more need it for multitasking with multiple programs.
Here are the specs to my computer

Mac mini (mid 2011)
2.3GHz Intel Core I5 processor
16gb DDR3 memory
Intel HD Graphics 3000 512mb

I do not know much about graphic cards but have been reading I may need a better graphic card.
This is how I have it set up now

HDMI 1 input going to thunderbolt
HDMI 2 input going to HDMI

I have it set up as 2 different monitors on my screen and it works decently. however it is basically 2 separate screens. What I would like to have is it set up for one screen and I can set up different windows from the one screen. When I only plug in one input and switch to widescreen; it is super streched and it doesn't look right (this is why I have it set up as two screens)

Just looking to see what my options are.
External Video Card??
Or if I have to get a new computer ?

I watched a lot of youtube videos and see others have it as one big screen and trying to figure out how to get that accomplished.

Thanks for help in advance