Here's what I did ...
I needed to take those trips in the fall, winter, and spring. That ruled out the High Sierra, and left me with few long-distance trips in central California.
I started with one weekend trip using 20 year old equipment lying around. Too heavy, but I'll cover gear later.
After a flurry of buying the wrong stuff, I did a couple more weekend trips.
Then I mapped out a 100 mile backpack loop through the Santa Cruz mountains, and long loops through Henry W. Coe State Park east of San Jose. So I planned five 100 mile trips using those loops.
On my first long trip I had serious equipment problems, including a fuel cartridge leak. I ended that trip several days early. And I rethought my equipment needs from the ground up.
My second long trip went well. Everything worked OK hiking 9-15 miles per day. I did have one scary off-trail adventure, and learned to always stay on well-traveled trails.
My third trip, in March, brought hail and sub-freezing temperatures on the second day – unusual for coastal California. My gear couldn't keep me warm enough. After one very cold, sleepless night, I ended that trip several days early.
For my fourth trip, in April, I planned to hike 16-20 mile days. After two days, I got a staph-infected tick bite because my tent entrance didn't seal. I had to end that trip early to get major antibiotics.
For my last training trip in May, again I planned to hike 16-20 mile days. I caught a cold just before the trip started – and after two days, I hiked out before I collapsed.
I had finished only one out of five training trips, and backpacked less than 200 miles. I was way behind schedule, but I had no more time available before August.
Next – Lightening up!