Hi All,
Does anyone has log file which shows some network slicing messages?
This is not visible to UE at all.
You won’t find anything about this in UE logs.
Thanks @RFSpecialist, didn’t know that.
So it all terminate at gNB?
Yes. For each slice networks books special resources and different settings.
Got that. Thanks 
You need to see Core network logs, more as in registration procedure AMF contact NSSF for configured NSSAI may be in registration request NSSAI there.
How many s-nsaai configured there, how many slices you create!
Few messages:
Registration request for configured NSSAI
Registration accept for selected NSSAI
Pdu session establishment request for upf selected for slice creation
Yes. Hard to find Core logs if you are not working directly in that department. 
8 are the max S-NSSAIs. somewhere I read it but not sure.
We have slice items which are around 1024.
Yes 8 n-ssai per UE.
1024 is slice differentiator.
It means per UE within slice you can differentiate given type of service.
Yes. With SD and SST in s-NSSAIs list.