Take note of which alliance you're in (A/B/C). It's listed at the top of your party bars. Some mechanics require you to go to a specific spot with your group, and going to the wrong one can lead to accidental wipes. A lot of raids will put A/B/C markers up to make clear who goes where. If not, your group is blue on the minimap and the other groups are green.

Turn down other people's visual effects, as with so many people it can lead to a LOT of visual clutter if everybody is on full. That will make the fights much easier to see.

Rest of the advice you've been given is great.