How to make a plane?

I’m trying to make a 2d game, and I’ve made a picture in Microsoft Paint and imported it into Unity as a 2D Texture. When I try to move it from the Project View to the Hierarchy View and onto a GameObject (by dragging it with the mouse), it won’t let me do so. What I’ve learned from searching UnityAnswers is that I need to make a plane then wrap this 2D Texture around/on the plane, but I can’t find how to actually make a plane. So that’s my question: how do I make a plane in Unity?

Big thanks to anyone who helps.

In the menu:

GameObject → Create Other → Plane

There is also a free script available on the Wiki, that lets you specify how many polygons in your plane. The default unity one is abotu 10x10 or 200 or so triangles, when you probably only need 1 quad.

Stick this in your /editor folder and you’ll get a new menu item to make custom planes.