I stole this from @Bryce in a related post for a Full Distance:
For starters, I would check out this resource I’ve compiled for Ironman athletes. There’s a lot of good info in there, and it may help answer a lot of your questions:
I would also check out another article that addresses what you should do when you have extra time to prepare for your event:
https://support.trainerroad.com/hc/en-us/articles/360025556952-Too-Much-Time-
These articles should give you the basic principals you need to build your season 
If you have any additional questions, feel free to ask!