FFF-File is NOT a factory-file but I see enough.
You have deleted in menue Extruders the left extruder >>> only Right Extruder present, while in other menues the Left Extruder is present. The Left must always stay present!
Please allow that I doesn't understand this and how to reach that missmatch, but I recommend to install the printer another time.
If origine has only one extruder, name it first Left Extruder, than add a new one named Right Extruder. Set in the menueTools the offset of the new extruder and add in menue Temperatures a new temp.-sensor. The Left stays as T0, the new Right is T1 .
The number of tools ( T0 / T1 ) doesn't play role for the heat bed, thats a little bit irritating but the heatbed doesn't need a T-number, therefore you can set there what ever you want or let it be T0 / T1 / T2 / T3 ....
I guess, in S3D-Tutorials are enough informations about installing an additional tool.
Using the Right it needs only to set in all menues the Right as active, in Menue Temperatures you must set for Left 0 ° AND uncheck the Wait_to... box .