My question is: How to keep the drawing on center while adding parts with the intentions of zooming? 

 I was learning the command scale. I started  with 10' scale via... You tube with how to. The drawing was gone, went to 5' worked down 1/64".  Now the drawing is tiny, large grid.

Also, going to zoom the drawing goes left, right, always readjusting to center.I will be sending you three images. As soon as I figure on how to learn insert/ edit image!

Unit System Precision Architectural 0'-0"

Angle type Deg/ Min/ Sec Precision 0d Block unit Inch

Enable Snap (F9) empty

Match Grid empty

Horizontal Snap1" also Vertical snap 1"

Enable Grid (F7) Ck

Rectangular on 

Horizontal display 1" also Vert 1"

Behavior: Enable relative dimension Ck on

Drawing Boundary Lower left corner (Both 0)Upper right corner X:2658, Y:2054.

Active Drafting. Set Styles all set for (standard). Scale factor 25.000

Thank You 

Greg