What new car would be best for my needs?

I need a new car for a family of three.
I need it for frequent, long road trips and city driving.
My requirements:
Sedan body
Automatic transmission
Good fuel economy
Comfortable ride
Reasonable cargo space.
I was looking at these:
Honda Civic
Honda Accord
Toyota Corolla
Any other recommendation is welcome.

You can do your own research and find out what's available in that style of vehicle by going here: https://cars.usnews.com/cars-trucks/rankings/midsize-cars

Consider a VW Passat. VW make very good diesels which are very economical with plenty of power. If you are not used to diesels test drive one of the higher powered models. You will be pleasantly surprised.

Any one of those is a good family car. The Accord is a little larger than either the Civic or Corolla. But even the smaller Civic or Corolla are fine for a family of 3.

I would also consider the Mazda 3 in that mix. IMHO, it's a more rewarding car to drive compared to the Corolla and Civic. If you're flexible on the sedan requirement, the 3 and Corolla ( in i'm guise ) are available as a hatchback and offer far more cargo capacity than the sedan versions. The Civic is also available as a hatchback but due to the steep slope of the rear hatch, it cuts into cargo space significantly.

All the vehicles you have mentioned are of very good and reliability. There are others which automotive appraisers suggest as well.

A bicycle built for 3.

The Civic will be too small if you take the family on a trip. Get the Accord. Best suggestion is to find one coming off a three year lease. It will be practically new, will have a warranty and you avoid most of the depreciation that you see with new cars. BUY it and then drive it until it drops.

Honda Fit.

A 2018 Camry with the 2.5 engine.

Toyota Prius. Carries 4 comfortably, and the fuel mileage is superior. Loaded a new 60" TV into the back with the rear seats folded down. It will go as fast as you dare go.

70,000 miles on it so far, and it's needed only regular services. Oil changes are every 10K using synthetic.

Mazda 3