The first thing to do is look up guides on dungeons before you enter them. It takes far less time for you to read a guide ahead of time than it does for someone to type out the rules for every encounter.

As far as speedrunning is concerned, most of the folks running these dungeons have already been through them dozens of times and want to get through them as quickly as possible, however trying to speedrun with a low geared/leveled tank, healer or even DPS can actually make the dungeon take longer if you're constantly wiping to big pulls. If that is happening, then let your party know that, because you are new and don't have the survivability/healing ability/damage output of an ilevel capped player, it would be faster to do small pulls and survive, than do large pulls and wipe.

If you aren't wiping, and your only complaint is that things are too hectic, then seriously, get over it. Any encounter you live through is a success.