Hi, I'm sure we can help but before we do, answer a few questions please.

how many sqft is the lawn?

do you have irrigation or a way to water?

are you open to a full kill/replant?

have you had a soil test done? Such as one from Logan labs?

what kind of grass are you wanting to keep?

full sun or shade?

that ought to get things started

Not sure of sqft. But would guess around 1500. Yes I have an outside water source to water. Depends on how involved killing and replanting would be if I would go with that way.No soil test has been performed yet. The lawn is mostly full sun, but the problem areas are shaded fromantic the afternoon until sundown. Any help would be greatly appreciated.

Yes, fescue is what you want. Look for one, or a mix, that is shade tolerant. Some are better than others, but most all are much better than the alternatives or rye and Kentucky bluegrass. The only other shade tolerant grass you might be able to use is St Augustine. That is a coarse bladed grass while the fescues are fine bladed, so they don't mix well.

Do you know what kind of grass you have now? Cannot tell from the altitude and bright sunniness of the photos. The best garden pictures are taken on shady days with no flash. If you need help IDing the grass, get about 3 inches away and take a picture. We can't always tell what it is, but we can often tell what it isn't.

Here's what is involved with a complete renovation.

Water the entire yard daily for a week to sprout any and all the weed seeds. Then spray with Round Up.

Continue to water the entire yard daily for another week to catch the late blooming weeds and spray again with RU.

Rake up the dead stuff and you're ready to seed. Well, if you see low spots or high spots you need to level it first.

Drop the seeds and roll them down with a rented water fillable roller. The idea is to press them into the ground to make good contact with the soil.

Water daily just enough to keep the seed moist, not saturated. Fescue seed should show about 80% germination in 2 weeks. Don't stop early.

If you start that now you will have time to evaluate the density of the seeding that took so you can add more if you need it more dense. Fescue is the type of plant that does not spread much by itself. It will not form a dense sod unless you seed it that way. Every August you should evaluate the lawn to see where you need to add seed in September. If you do not the crabgrass will find those thin spots the following April.