I just bought this dwarf jade plant

from a local farmers market and am wondering when to re-pot it, and start training it. Also, I would like to know if it will mature enough to be re-poted in the proper season.
Thanks to anyone who can help.

Welcome to the Forum, MJ.
The Jades (Crassula Ovata or Portucalaria Afra) are succulents, and not considered as bonsai, even if many bonsaists manage to create "images of little trees in fancy pots" with them.
They are very easy to grow, very easy to propagate by cuttings, and don't like it wet (they like to have dry feet).
You can repot it anytime, but if I were you I would buy some plants more appropriate to bonsai, besides this little Jade.

Thanks A Lot! That's really helpful! I will look into something like juniper or maple instead.