@brokenbat,
The season is from May to August but as some guys stated earlier that practice games commence in April even while if your team does good, then you can play till September.
Indoor facilities are decent, there are lots of them in outskirts of Toronto while some fall in 6 side.
TDCA is creme de la creme and most competitive, others leagues higher divisions are competitive and good.
You can always reach out and message me for any question regarding Toronto, I play in few different leagues for few different clubs.
Hope this helps.