The easiest quilt is probably something with a layout like subway tiles or a brick wall, where you don't really have to match any corners or worry about points. You can just pick colors you like, pick a "brick" size, and put it together however you like - scrappy/random style, or arrange them into lines or v's or zig-zags.
One of my first quilts was that style; I used 4x8 bricks and it went together nice and easy. (4x8 finished size, so cut at 4-1/2 x 8-1/2)
If you use batting with a minimum quilting distance that's larger than the short side of your brick, you can do stitch-in-the-ditch sewing along the long straight lines and that will be plenty of quilting. Then if you feel like getting creative, you can FMQ in all or just some of the bricks.