It's grass yo, if it wont grow either a) it's a soil problem or b) something is eating all your grass seeds. B is pretty easy to take care of, just put down straw or old grass clippings over the newly seeded stuff. A goes from digging up the really dead spots to just getting it aerated (which you can do yourself with a graden fork).
Idk my yard is SAND, so shit doesnt want to grow in it normally. I used to live somewhere it was clay, but compaction and chemical burning are what normally cause problems. Shit wont grow in it if it feels like walking on cement, nothing will grow in it if you constantly walk on it either (also causes it to have the texture of cement). If you fucked up with artificial fertilizers you also mightve burned it. In all these cases the best solution is to: redress the soil.
Grass grown best in loose dirt high in nitrogen, that means fork it and lift just a bit so you can feel it start to break apart. Then rake vigorously with a metal rake, enough to get some dirt going on top. Then put down some peat moss mixed with composted cow shit, available everywhere? Just enough to get a lil dirt on top. Sprinkle some seed, I normally walk back and forth over it once to push some seeds in, water gently, do not soak it, it makes it compact.
Same thing in totally dead spots cept use a shovel to turn over the soil like you were making a garden.
THEN DO NOT WALK ON IT. DO NOT LOOK AT IT. AND DO NOT APPLY FERTILIZER. You will have grass n a few weeks, just forget it's there, grass IS A WEED, it will grow. You also wont have to mow it for a few months, it'll look wierd but mowing it too soon will just kill it.
Dont use herbicides, hand weeding is ftw and do not weed clover, it is fucking > than grass, it gives back to the soil and it's green anyway. Dont soak your lawn. Dont mow too close, actually the longer the grass is the less weeds youll get. Dont get suckered into buying expensive ass grass seed either, normal contractor grade bermuda/bluegrass mixes are fine. Chemical fertilizer is meh, you shouldnt need it unless you have pro sports played on your lawn, composted manure sprinkled in spots that dont look up to snuff usually does it.
If it's a water problem ignore this.