A 341 hearing is the so-called "creditors meeting" that every bankruptcy filer must attend shortly after you file your bankruptcy papers.
For many filers, this will be your only trip to the courthouse. This is when you meet with the bankruptcy trustee appointed to your case, and are asked questions about the information you have entered on your forms.
Most court websites post schedules of 341 hearings, and when you file, you will be notified of your hearing date. When you show up for your hearing, you will find that many other people have hearings set for the same day. You sit wait for your name to be called.
This is also the time when creditors can ask questions about your papers, and objections to your filing may be raised by creditors.