It seems like you are having problem with Meshing. Having look at your model Geometry, We can see that your model is inputted as IGES file format and contains only shells. The meshing algorithms on Simscale requires Solid geometry to mesh. So, you can input your Geometry as a STEP file and make sure the Geometry contains solids. Also, if your Geometry contains multiple solids, you can reduce them to single solids and simplify as much as possible. For more information regarding how to merge the solids you can have a look at this link.
You Geometry looks symmetrical, so you can only use half of your Geometry and apply symmetry boundary conditions.
Hope this helps! If you have any queries feel free to contact. Happy Simulating!