When it comes to Lenses, a lot of Photographers speak of the Holy Trinity of Lenses. What that means is, that there are only three Lenses that you need to be able to do any kind of Photography.
Usually, those Lenses are a 16-35mm, a 24-70mm and a 70-200mm. But those only really do the Trick on Full Frame Cameras, since you need to take a Crop Factor into account on APS-C. For Canon, that Crop Factor is 1.6. That is where the Unholy Trinity comes into play.
For Canon Shooters, this Unholy Trinity consists of the 10-18mm Lens, the 18-55mm Kit Lens and the actually quite fantastic 55-250mm Telephoto Lens. With those three Lenses, you cover an equivalent Focal Range of 16-400mm. And you can get all that for less then a 16-35mm L Lens.
The Unholy Part comes in when you consider the built of those Lenses. In Contrast to higher Quality/ higher Price Lenses, they are made mainly from Plastics. The Lens Mounts are Plastic, the Bodies are Plastic, and not one of the Lenses is Weather Sealed.
The Image Quality on the other Hand is actually quite good, even with the 18-55mm Kit Lens. The Apertures are quite slow though, starting between f/3.5-f/4.5 at the Wide End and always going down to f/5.6 on the Tight Side. That is not that much of a Problem for me though, since I tend to use my two Prime Lenses when I want to have fast Apertures.
With those Lenses, you can theoretically shoot everything you would ever want to shoot. But usually, when your Photography becomes more sophisticated, so do your Lenses. In this way, both Trinities are a Starting Point, but nothing else. But they are a good Starting Point nonetheless.