You have to go to Project Schematic and set properties in Engineering Data cell. If this is linear analysis you will need only density, youngs modulus and poisson's ratio to determine each material. You can try to add also properties for checking Safety Factors - in default material like Structural Steel there are four materials data included: tensile yield strength, compressive yield strength, tensile ultimate strength, and compressive ultimate strength.
Then you should go to To Mechanical and Add Insert - Stress Tool - Max equivalent Stress. And this result can help you to analyze your system.
Different aspect is that you should check all contacts status via Contact Tool and all boundary conditions (check their influence on your model). If you want to analyze Life of your parts, you have to input Fatigue data and use Fatigue Tool.