Queue and Enter dungeon In party chat say "this is my first time in this dungeon, can you let me know if there are any mechanics I should be aware of? No spoilers though please"

If they talk to you: great, usually they will give you tips before bosses, otherwise pull a cluster of mobs at a time. If your hp doesn't make you panic consider 2 clusters at a time. If you go the wrong way they will let you know most likely. Dungeons are short and the penalty for error is minimal.

If they don't talk to you: great, then they won't complain probably. Do your best! Most dungeons are petty self explanatory, but some under 50 have parts people usually skip to streamline.

If people are rude to you: pray for their friends and family through for the burden they carry daily.

Honestly I'm a salty bish but I only ever see people get upset when someone dies to the same avoidable thing several times (more than 2x) at boss stages in dungeons or in trials without asking for advice or acknowledging their error.