Concerned about time and which plan to execute. We will be traveling to the Boston area in mid to late October this year and plan to visit surrounding areas as well.

I’m thinking of taking a Sunday to rent a car and go see Lexington and Concord because that day we have unlimited time.

We fly out on a Wednesday at 6:30 pm, so planned to do Adam’s historical park and take the trail from Quincy.

Does this sound right time wise? Should I reverse this plan?

That would probably work. Do go to the NPS web pages for the parks and check out hours, special events and closures for the days you plan to visit. Note also the policy on the size of bags that are allowed in the buildings

I think that's a good plan. A lot of Minuteman NP is outdoors so you can visit anytime during the day. It's fairly spread out.

for visiting the Quincy historic park, just make sure you have an early start and aim to get there at 9am so you can take the first tour at 9:30am. Make note of their other tour times and free shuttle schedule as the sites are spread out. Are you staying in downtown Boston? What about your luggage as you cannot bring that to Quincy historic park. So leave yourself plenty of time to return to the city to retrieve your luggage before heading back to Logan.