Help me with a training plan and logistics

[Owlie]

I am confused as to what you want to achieve? Just the 100? Is your rail trial multi use? I have a hard time imaging wanting to do 100 miles on that, with kids and horses and strollers. Also why July? Why not later? Why not ride on the road? The best and only way to ramp up mileage is just to get on your bike and ride. If time limits that, then adjust your plans. I get the idea of having a goal, but you have to ask yourself why you want this goal? As it is not an organised ride, you can fix the day and date for whenever.

It's a multi-use trail, but between the main access points, it's mostly cyclists. And maybe we're just really polite here, but I've had relatively few problems.
Basically, I want to ride the total length of this trail (it's quite long, and it comes out to be about 100 miles, possibly more), as it's what got me to fall in love with riding. It's been a goal of mine to do it before I left Ohio, and this summer will be my last chance for a long time.