Party finder isn't much use for dungeon groups, people will generally only check it for endgame farm groups, and almost nobody specifically chooses to do low level dungeons, they just do them for roulettes.

Honestly, the best thing you can do is stop caring what people think. Everyone was new and undergeared once, and a player who can't adjust their playstyle to cater for that is as much of a problem as the new person. Tell people you're new and it's your first time, and if they don't like it they're free to throw a tantrum and ragequit while you get to requeue instantly.