If I had 2 otterpus on turn 2 that conquered, do I draw 2 cards instead of one?

No — you draw 1 card, not 2.

Otterpus's ability is a replacement effect ("would score 1 point... draw 1 instead"), and Rule 370.2 states a replacement effect can only be applied once to an event or to the events that replace it. When your first Otterpus replaces the scoring event with "draw 1," that draw is no longer a scoring event, so the second Otterpus has nothing to replace — the two copies don't stack. If you control two Otterpus, you choose which one applies (Rule 372), but the result is the same: one draw instead of one point.