You're near the border of the transition zone. Would you know what grass type that is? It could be a southern lawn type or a northern and it's hard to tell.

It's probably a southern, but...

The elevation of his property would also help. That area is on the edge of the mountains. Also Lake Norman could affect his the grass he can grow, as it would affect the local environment.

I don’t know, when we bought the house the grass was in much better condition. Here’s a picture soon after we bought the house over 2 years ago

Let's see if we can get @dchall to chime in here, but I'm going to go with an initial guess of Bermuda. due to the mow height (very short) and the fact that it's clearly flourishing at that.

Let's try to validate that. Do you generally mow it at less than an inch? And it's OK with that?

I have the mower set at its highest setting because someone told me that’s the best way to mow grass. Don’t have much grass now because the weeds have taken over my yard. We thought maybe it was bermuda when we moved in. I think I threw some fescue in the backyard sometime last year

OK, that's a weird mix. :-) Now we really do need @dchall to chime in. He'll be able to help straighten this out better.

Fescue would be mowed high. Bermuda very low.

But for starters, even if it's a strange mixed lawn, either of them are going to need feeding. Bermuda is a heavy feeder (monthly during the growing season). Fescue is a mid-range feeder (three times during the season at fairly carefully timed points). Fescue is kind of touch-and-go where you are, but it was a better choice than others you could have made (KBG might have done the job, rye wouldn't have done very well at all).

When it's fully back and greened up, in active growth...I mean, you're probably there now,, but let's say April first unless David comes along and tells you otherwise and that this is a northern grass.

Any good high nitrogen fertilizer will do the job, and get the cheapest, There's nothing magic about fertilizer, and a no-name is as good as anything else (and I approve of no-name fertilizers, using the most no-names of the no-names myself--brown-bagged urea).

Just look for something with a high first number, and low second and third numbers. So examples would look like 35-0-3, 36-2-5, 41-1-2, that kind of thing. Those aren't exact, just examples. And something that does NOT advertise a lot of slow release nitrogen, it's expensive and you don't need it.

Feed at bag rate, however they suggest. You can even feed a little lower than bag rate and step closer than recommended--that's what I do to assure even coverage.

You can water it in if you want, but nitrogen fertilizer won't harm children or animals, although it's salty and might slightly irritate bare feet and paws. Wash it off if so.

For Bermuda, do that monthly during the growing season.

If this turns out to be fescue, appropriate dates would be May 10, September 15, October 15, and November 15. But we have time to figure that out before dropping too early.

As per the weeds (separate because that was a book) your Big Box store will have plenty of herbicides safe for Bermuda...but let's verify what you have first. I am not good at Bermuda ID, and some cultivars have some peculiar sensitivities.

It looks like a dog pee lawn. Good luck.

Even those are easy to handle. Use carbon-based organic products to increase the bacterial population to bind the urea-based nitrogen pouring into the soil.

It's a bit of a multi-year project, but it's simply long-term, not particularly difficult.

Or, don't scare the customers. :-)

I'm going with a mix of northern (the green stuff currently) and warm season (the brown stuff).

With that much shade, bermuda is out of the question for a long term solution. It would be good for the ability to rebound from dogs and a child. If you did not have dogs I would suggest St Augustine; however, in the winter, the dogs will tear it up pretty badly during dormancy. I think this is a classic dogs/kids/shade conundrum.

If you just want it to be grass and do not care as much about being the nicest on the block, then drop some preemergent herbicide now and in mid April, spray any weeds you see with Weed-b-Gon. The wbg should take out non-grasses and leave you a mix of whatever you already have.