Sure, for the most part, you do.  The exact type depends on how big your lawn is and where you live.  For example, you might need a type of fertilizer for sandy soil, or for big lawns in a city, or for smaller lawns in the country, and so on.  I’d recommend using a product from the place you buy fertilizer, which should have more information about what they recommend.
assitant
The lawn should be fertilized if it is looking pale, not as green as it should be.
assistant
How do I take care of a lawn?
user
You’ll want to do some weeding and mowing, as well as fertilizing and watering.
assistant
Okay, how often do I do that stuff?
user
Every few weeks, or when you see the grass is getting tall or less healthy-looking.  Can I recommend you do it about every three weeks, depending on how the grass is doing.
assistant
All right, thanks for that.
user
You’re welcome!
assistant
Do I need fertilizer?
user