I'm new to blender and just trying to play around with the particle system though I can't seem to figure out how to rotate these petals. I'm sure there's a simple answer. I just want to rotate them flat but changing the phase in the rotation tab doesn't help, it just rotates it around a weird point.
If the Phase setting isn't rotating your particle correctly, it's very likely that your particle isn't oriented on the correct axis.
Objects used as hair particles do not view Z+ as "up". They must have a different orientation, for some legacy reason coming from the particle system's beginnings, afaik.
The default particle orientation can be changed in Object Properties -> Relations -> Tracking Axis. It is +Y by default, changing it to +Z will probably make more sense for most people.