I suspect you'll like the folks over on the lawn forum and you should really ask them about aerating etc., but here's for now.

Watering deep is a must. If you water just a bit every couple days, then the plants are sure you will always and forever do that, so they make all their roots right at the surface of the ground. Skip a few days and they will have shriveled roots and dying leaves. OTOH, deep watering makes the plants put their roots deeper, which is desirable because there is [usually] more moisture lower plus more nourishment. BTW, if you use a sprinkler, set an empty small pet food/tuna can in the area to be sprinkled. When it's full, you will have watered about an inch, which is sufficient for a week. And you are likely going to be amazed at just how long it takes a sprinkler to put down an inch of water. Sprinklers are a very inefficient form of irrigation, losing as much as 80% of the water to air absorption.

I am not a good person to tell about fertilizer because I don't care for most commercial fertilizers. I sprinkle compost over the lawn in the late winter/early spring, and then spread CMG 3 times [6 weeks apart] as a weed control. The CMG also provides a bit of nitrogen. OTOH, I consider grass a provider of oxygen so I want healthy plants, but I don't really care whether it's golf-course green in color.

Dethatching is needed only when there is a build-up of thatch (the dried grass/weeds at the base of the grass plants). Thatch is less of a problem if you use a mulching mower and trim no more than an inch of grass at a time.

Aerating is just what it says, and if your lawn is trying to grow in heavy clay or similar unimproved soil, you might be happier if you aerate occasionally. They have lovely machines to do this (rent, don't buy) or you can stroll up and down your lawn while stabbing it with a sharp pitchfork -- don't do this if it is muddy (your feet will pack down more than the tines can loosen) or if there are small children or pets nearby (because it is possible to break a tine on a hidden rock).

Now you can go over to the lawn forum and ask for details, lol.