I need advice on how to properly upkeep my garage car.

I bought a new LX in 2017, my daily driver is 1990 Civic LX.

The 2017 LX sits in the garage; I drive it once a month, about 30 miles or so, and on out of state road trips. It currently has 21,000 miles on it.

Since 2017, I've changed the oil and filter twice, rotated the tires, and changed the air, cabin filters. That's it...!!

What I don't know, understand, is how important is the Honda Maintenance Schedule where it says: "Service at the indicated distance (miles) or time (months) - whichever comes first."

How much of this periodicity maintenance do I need to do?

I've had the car over 84 months, based upon that, the car should have had every service listed in Honda Maintenance Schedule.

Advice on how to approach this dilemma is appreciated.

Thanks.