Sure.
few things that might help right away.
set Units
Preferences > Construction options > Units
information window to manually input numbers or attributes
Window > information > information window
CTRL + 5 is the hotkey
There are basically 2 options for transforming objects (Move, Scale, Rotate)
ABS = Absolute Numbers that you type in are based on the origin 0 0 0
REL = Relative Numbers that you type in are based on the relative location.
when in a transform tool, look at the prompt line.
-hit the "a" key on the keyboard and hit enter. now the input is Absolute(ABS).
-hit the "r" key on the keyboard and hit enter. now the input is Relative(REL).
when typing numbers into the prompt line, you dont have to use commas, only spaces AND you dont have to type the whole thing out. aka. if you are only moving in Y direction 10 mm it would look like this (0 10 hit enter)
moving a Curve 1" to the left would be based on what axis you want to move along (look at the little XYZ indicator in the lower left of the window. (RGB = XYZ) lets just say it was in the Y direction. Go into the MOVE TOOL. the prompt line is automatically waiting for you to type something The fastest way is to type "r 0 1 Enter" if you are all ready in Relative mode, then you dont need the "r". just "0 1 Enter"
for the Circle there are 2 ways.
create the Circle with a Keypoint curve, this allows you to just type in the diameter or Radius. use the information window to change the radius/diameter attribute.
the other is to make a regular Circle and use SCALE to make it 12" Select Circle, Select Scale tool, Type "a 12 Enter". this makes the circle absolutely 12" if the prompt line has a ABS then you dont need to type the "a". just "12 Enter"
hope that helps and does not confuse you : )