Here is your parts breakdown.
Replacement parts for General Electric GSD4010Z00AA Dishwasher | AppliancePartsPros.com

With luck you will not have to replace anything.

Clean the spray arm, often I find it is easiest to run water into it and then pull the food particles out of the holes using tweezers.
Note: This would not be the cause of poor draining but will give poor wash results.

Remove the sump cover (Item 506 in Section 2) and check/clean it.
Be careful as there is often glass is the sump.
Also check that there is nothing wrapped around the chopper.
Take note of how the inner piece goes in because if you put it back wrong the chopper will eat it.

Remove the rear screened cover (Item 543 in Section 2)
And remove the piston & nut, it unscrews.
Check that the piston and nut is sealing OK.
If not replace it.
This is a common cause of poor draining since if it does not seal then during drain some of the water flows back into the tub instead of out the drain.

Take a look down the pump throat (item 310 in Section 3) to see if the seal/bumper in the center of the flapper valve is still there.
If you click on the picture of Item 310 a new page will open with more views.
Click on the center picture and you can just see the seal down the throat (little black nub)

If you still have a problem, undo the drain hose at the house plumbing and check that it and the drain is clear. This is a common spot where stuff can clog and cause problems.

You may want to try draining it into a pail, Hold the drain hose securely and put a towel over the pail so the water does not splash all over.
If it now drains OK, you probably have a plumbing problem.