Straightforward. Add 10% per week to your weekly distance. Ride 2 or 3 weeks high volume, then 1 week easy. By the time you get to each goal event, be sure you've ridden at least 1 ride that is 80-90% of your event distance. If you're planning on riding in the dark, make sure you have good head & tail lights plus high viz clothing, also consider a helmet light. Practice riding in the dark.
If you don't care about speed, don't ride intensely and this will simplfy nutrition, just consume 200-250 cal/hr plus 16-25 oz water/hr, depending on heat/sweat produced.