Is it safe if you use two jacks on one side of the car? I'm trying to get both wheels in the air simotaenously, basically.

Generally, the more wheels on the ground, the better.

i dont think its any safer or less safer than using one jack, although if one falls you have one that could still possibly hold up, hehe.

if you position the jack under the car just behind the mirror, both wheels on that side of the car will be lifted at about the same time.