Note: Take care to face the trap the correct way. It may be tempting to turn it the wrong way to fit it into a small space but it doesn’t work properly this way and has a tendency to leak.
This is where it all comes together so make adjustments as necessary and remember to grade down and the pipes go back toward the wall. Line everything up the way you want it before tightening the joints. Make sure everything is tight and glued into place.
Run water to check for leaks. Tighten up anything that leaks and then fill up the sink and give it a good volume test. Do this for both sides of the sink to be sure everything is working properly.