Whenever I right-click in the hierarchy or click the game object tab for the drop-down, there’s no option for 2D game object only 3d game-object. I just booted up unity after a long time and I could find the 2d shapes easily before. Right now I’m stuck creating a cube instead of a square.
Pls help!
You can always make a blank GameObject and add a SpriteRenderer component and get exactly the same result with just a few extra clicks.
It might be that Unity has moved the 2D stuff to a package in later versions of Unity, whereas it used to be built in. Look in the package manager for something, such as perhaps Sprite Editor or Sprite 2D or something.
If you had a larger array of different shapes, this is likely because you had a third-party package installed that offered this functionality. You would need to move that to your current project.
Did you find any solutions to find 2D primitives in Unity?
Pretty sure it just became a package and now has to be added via the Package Mangler.
I don’t have Unity in front of me right now otherwise I’d tell you what the package name is, but search 2D, perhaps 2D Sprites or Sprite 2D or something.
What packages do you have installed? You’re asking for a solution but don’t provide any information on your set-up. There isn’t a solution for an unknown setup, no. 
2D has a suite of packages and even a feature set for 2D that has all of them included (see the Package Manager). Create a new project from the 2D template to see them.
The 2D Sprite one is the primary one you need though at a minimum AFAIK.
Add 2d sprite package in the package mananger.