After 1.d4 d5 when white plays 2.C4 that’s called Queens Gambit. The purpose of playing queens gambit is get control of central squares d4 and e5.

After 2.C4 black has two options.

1. To take the c4 pawn
2. To decline the offered pawn and play like e6 or c6.

Both moves are played at high level, and you can choose one of them. Both moves from black side are solid.

From white side, white will put as much pressure on the central pawns as he can.

It’s my suggestion, if you want to play queens gambit with white pieces, you should watch games of these top players:

1. Garry Kasparov
2. Anatoly Karpov
3. Anand
4. Magnus Carlsen