Status bar gives information on how to use the active tool
You can hide it if you click and hold and drag down on the bottom margin and drag down.
To show it again, click on the bottom border of the interface and drag up.
To maximize an area, hover over it and press CTRL+Spacebar, if you are on Windows. There should be something equivalent on each platform, such as possibly COMMAND and Spacebar.
Each area that is for viewing has an editor.
You can control and view scene information with it.
You can join, split, and scale areas.
This is very specific to Blender and makes it unique and is a stand-out feature compared to other 3D packages.
Blender tries to not have floating windows but to split the real-estate up into sections.
To scale, left click on the mouse and drag an edge of the area
To split areas, right click on the mouse on an edge of an area and choose split
A perpendicular split line will appear to split the area in the adjacent area you mouse over.
To join areas, right click on the mouse on an edge of an area and choose join.
An arrow will appear to show which area will be "stomped" over be the other area.
Another and probably faster way to join areas is to hover over a corner of an array until the icon becomes a cross. Then you can click and drag a new area.
If you drag it into the current area into an area that does not contain the corner, you will merge the areas.
Practice it. If you mess up, start a new scene to get the original layout