Lay Out the Lumber
It's much easier to build the wall frame on the floor, then pivot it up into position. Lay out the 2” x 4”s for the wall frame with the studs 16" apart (measured on center). Use pressure-treated lumber for any part of the frame that will come in contact with concrete; for this basement wall, that means the sill and one of the end pieces. If this wall will have a door, leave one or two studs out of the layout to make space for it.
When buying 2” x 4”s, pick the straightest ones possible for a good, squared-off wall frame. Use #1 or #2 grade pine; the quality goes down as the numbers go up.