Unless the OP doesn't even own a bike, he can practice on whatever he owns now. Most parts are extremely simple to install. Many have one bolt. How tough is it to install one bolt or nut?
The BB cup installation does require special attention. The BB width must be 67.2-68.8mm (step one). The BB shell threads should be checked for squareness to the BB faces. This can be done by threading the cups into the frame, just until they contact a .010 inch feeler, then using .008-.012 inch feelers to check for high or low spots. If either if these tests fail, it's off the to bike shop for facing and a recheck of the BB shell width. Once all that's done grease the threads and torque to 35Nm. You must have the proper BB cup tool and a torque wrench.