Here's my routine:
Early Spring (when forsythia blooms) apply an organic fertilizer which usually is composed of various meals with bone meal the most abundant. Look for one that has corn gluten which is a pre-emergent weed control. (Prevents weeds from sprouting) I use Gardens Alive Wow Supreme.
If you lawn has an extreme weed problem apply again one month later.
To get rid of existing weeds use any organic herbicide that has d-limenol and/or clove. These are essential oils. The d-limenol is a citrus oil. They burn what ever plant it is sprayed on including morning glory so only spot spray your dandelions and weeds. Spray any weed that pops up. Be diligent in early spring. By summer very few weeds appear, and you are just enjoying your lawn.
Early fall, September, I fertilize again with a dry organic lawn fertilizer. I use WOW supreme but you can use one without a pre-emergent weed control.
You can reseed bare areas and add compost if needed. I only aerate when needed which hasn't been very often.
Keep the lawn mowed regularly.
Watering depends on your soil type and the type of lawn you have. There are also conditions created by your house and the sun that may effect how often and long you water. I have west facing second story windows that reflect sunlight and almost burn the grass. The type of sprinklers and their output will also effect watering. I have Kentucky Bluegrass and a sandy loam soil. In spring I water as needed. In summer the sprinklers come on everyday for 15 minutes. You can always cut back the water and if you lawn complains increase the time.
Be sure to choose the right type of lawn for your purposes and concerns. We have a green zone all around our house because we have frequent wildfires and this acts as a buffer zone. Different varieties feel different, grow different, have different water requirements, different hardiness and green up at different times and rates. So do some research so you are happy with your choice.