You should not be studying openings at 1138. You should be focused on opening concepts only. Control the center. Develop the minor pieces first. Don't move pieces multiple times. Etc.
That said, based on one opening concept, control the center, Black has a strong point on d5 after 1.d4 d5. White tries to disturb it with 2.c4. Black, if he wants to maintain his strong point, must protect his pawn with another pawn. Therefore, you should play either 2...e6 or 2...c6. Both have their detriments. 2...e6 makes the Light-Squared Bishop have limited scope. 2...c6 impedes the Black Knight from developing to its most natural square. Pretend that you have never heard of the words "Queen's Gambit Declined" or "Slav Defense" and approach the opening phase of the game as described above until you are at least 1600 and preferably 1800.
i am around 1138 [live chess] and having trouble selecting the best reply to the QG that is not the Albin Counter gambit. there's too many options to choose from and i need help.