Ssangyong Rexton engine light on, fuel gauge pointing straight down, engine wont start.

Is engine turning over ?

Yes car spinning fine ...just not firing at all..there is 1/2tank of fuel.

Could get an easy start aerosol can and spray into air intake and see if it fires up before getting too involved . . Another possible cause could be the crank sensor .

Easy start is dreadful stuff.
You really Must get this car connected up to a proper Diagnostic scanner to evaluate the issue otherwise more damage could occur.
The vehicles immobiliser may be on which will turn off the fueling or pump etc, so definitely no start. If the car was was running fine and suddenly is not then think what has occurred between the two events? Did you drop the key? Gave you tried the spare key, anything new just fitted? Any warning lights recently (on for a while then off etc)?
Cheapest option is get car connected to a proper scanner with someone trained to read it.

" Easy start is dreadful stuff. "
Whether you think tis is dreadful stuff or not is irrelevant as it was suggested as a temp measure to see if car would start and thereby indicate a fuel problem which could then be pursued further .