Frame FEA

I'm currently switching over to Creo Parametrics Academic version with the goal of designing a frame for SAE Baja. I want to do a FEA of the final design in order to take off members of the frame that aren't necesary to make it lighter. Before I dedicate the time on designing the frame I want to do an FEA of the main hoop to make sure I know what I'm doing and can't seem to find any resources of what I need. Do I have to tell it to weld the joints? How do choose the metal for the material? How do I make custom OD's and wall thickness on AFX? How do I get FEA to work on Creo Parametric? Help on any of these questions would be greatly appreciated. Thanks.