NAIF completed a domestic training class in November, 2017. Dates for a future class have not been selected.
Check NAIF's announcements page for any current training information.
The European Space Agency will offer an introductory SPICE training class at their ESAC facility, outside of Madrid, Spain, around the end of June 2018. Consider watching the ESAC SPICE training website for details.
It may be possible to hold classes elsewhere, with support from the host and with NASA approval.
If you are interested in SPICE training classes you might talk to your space agency's management about hosting a local training class.
Self-training is another option you might consider. This option makes use of the same tutorials and lessons used in the live training classes.