There are a few ways you can find your required textbooks:
Check in the Course Readings tab in MyUni
Open the relevant course in MyUni;
Open the Course Readings tab in the grey navigation menu;
If you have required texts they will appear in this list (often labeled 'required reading' or textbook);
Check whether your textbook is available electronically or in print. If it's electronically available you can access it from any computer. If it's in print you can check where it is available and request it.