The next SPICE training class will be held in the area around Pasadena California in the Spring of 2019. See NAIF's "Announcements" webpage for more 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.
Some foreign space agencies may offer local SPICE training opportunities. Consider contacting your local SPICE leader to see if there are plans for local training.
Self-training is another option you might consider. This option makes use of the same tutorials and lessons used in the live training classes.