This is the stroke options

This is the color options,
You can use the stroke option and configure the settings or simply click on the fill color and configure the settings.
On the main menu we have a button which looks like a magnet like this

You can use this button to simply snap the objects in place.
Lets draw an oval on the stage, with the oval tool selected, lets say we want to give it a red fill, easy enough we simply go to this fill color and select red here.

And lets say we want a blue stroke,

If you really want the stroke to stand out, lets make it thicker than it is, by simply dragging the arrow to its right or by type in  a figure in the box.

Lets draw an oval on to the stage, so click on the oval button and go to stage and draw an oval, as you drop and drag, you will notice that as you drag it to a circle, it will  snap into place, now release the mouse button, you will find a perfect circle with the colors you chose.

You will see a blue bind box along the circle, this means that the circle has been selected on stage. You can make changes to this object, while it is selected, by simply choosing he fill color and the stroke color. If you don’t wan the circle to be selected on stage, simply press escape button on your keyboard, it will deselect the circle on stage.
By default the snap object buton is turned on, while selecting an oval tool, now you can draw a perfect circle by turning off the snap button by simply clicking on it, the background will disappear on it.

Now draw the circle by dragging the cursor on the screen and dragging it down by simply holding on to the shift key on the keyboard,
You can select all objects on the stage by clicking on each, or by simply hitting ctrl+A key in your keyboard and delete it by hitting backspace.
Now if you want to draw a circle exactly in the centre of the stage, you can draw by simply pressing the alt button on the keyboard and dragging it, it will uniformly expand in all directions.
Now lets make a rectangle on stage, you can click on the right bottom of the oval tool and you will find a rectangle, click on it and draw a rectangle on stage.

The rectangele tool works very similarly like a circle or oval tool, you can also use the snap objects to draw a rectangle, with snap objects on, you can release the mouse button when a circle appears at the corner of the square, it becomes a perfect square.

There is another panel called rectangle options on the right panel space, if you want rounded edges to your square you can use this rectangle options and type a number in the cells provided to get the corner rounded edges. Like illustrated below:

You will find something like this

Sometimes you will not know what exactly should be the rounded edges on the rectangle or square, there is another way to do this, you can simply click on the rectangle tool bar and draw a rectangle on stage, and do not release you mouse, you can now simply use the up and down arrows to know how much of rounded edges you want to have in the rectangle, this will give you an indication what you square or rectangle will look like with rounded edges straight away.