Arrive DFW 08.15 am Depart 24 hours later 05.30 am October

So 24 hrs in Dallas.
What do you recommend ?
I am older generation, I will not be renting a car, so Uber / Lyft everywhere.
How do I get a feel for Dallas in a single day?

As a history buff I strongly suggest the 6th Floor Museum at Dealy Plaza. If you're a football fan you might look into tours of Jerry World.

If you will tell us your interests we can offer more help.

History, definitely.
Local culture a big yes.
Shopping, possibly.

Football not at all.

I second the Sixth Floor Museum at Dealy Plaza recommendation. We also were in Dallas on a quick trip (college tour) and took the teen children and it was worth the time. For those not familiar with the museum, it's in the old Texas School Book Depository building, the location from which Pres. Kennedy was shot.

If the above doesn't interest you then consider Ft Worth. Ft Worth has a terrific museum district as well as the Ft Worth Stockyards. I've never been to the Stockyards but tourists seem to love it. I have been to the museum district and I highly recommend that.

The museum district in Fort Worth is surprisingly awesome. Especially like the Kimball Art Museum.

Another vote for the Sixth Floor Museum in Dallas. We had half a day in Dallas and the Sixth Floor Museum had to be a life changing event for me and my husband. Why? Because we were total conspiracy theorists until we went there. Our prior perspective was that it was way too far away for Oswald to have made the shot. Looking from the window to the road where Kennedy was shot, it was so close, a tiny pistol could have taken a person out. Dispelled our theory for good!

Thanks for the recommendation for the Sixth Floor Museum of Dallas. Our daughter and her family recently moved to the DFW area and we have visited several times. Will be going again and will want to visit the Sixth Floor Museum. I remember very well the day JFK was assassinated and where I was, and how horrified everyone was.

To the OP, I can definitely recommend the Fort Worth Stockyards. They have a cattle drive every day, twice a day; I think at 11AM and then again at 4PM. Although during a heat wave they cancel the 4PM cattle drive. We were there last October and this past July. We visited the Forth Worth Science & History Museum which includes the Cattle Raisers Museum, very interesting.

In Dallas, we really like the Perot Museum of nature and Science.

We spent a wonderful day at the Dallas Museum of Art, one of the top art museums in the U.S.

I think I have to be getting old. What came to mind was lunch at the Mansion at Turtle Creek.

But I'd still probably choose that.