blender has sevral modes, the one you want to be conserned with is edit mode, witch is slectable in the menu to the right of the object menu, in the 3d viewport headder. tab also switches between edit mode and object mode.
when in edit mode to the extreme right of the headder there are for buttons(4 dots, diagonal line, tringle, cube) there switch between salect modes(verts,edges,faces) the cube enables/disables back face drawing.
use the b key to box salect.
blender is bacwords becose the right click button salects, left button moves the 3d cursor(the read cercle) but im not going to discribe how its used.
when you have somthing salected press e to extruse(try out the difarent options
) this can be constrained to an acsis usung the x/y/z keys(z acsis is up in blender)
g key grabs salection and lets you move it
s key is scale salected
r key is rotate, all these can be constrained to acsess same as above
loopcut (controal+r is verry handy)
any questions?, ask away!
sorry about the spellings(dsylexic)
i hily recomend you download and watch all the tutorials on blender.org
learn blender, you will never regret it.