Hey ellalee17,
Thanks for posting on the forum.
With an incompressible simulation, you need only one solid body representing the flow volume.
It seems like you have 3 solid bodies. You might want to use Boolean operations, etc. to subtract the two inner bodies from the outer solid body to create a single flow region with hollow space that represents the boundaries of the inner bodies.
Any of these tutorials should be really helpful before getting on with this simulation:
Best,
Satvik