Hi, thanks for your question.
The best place to find second reading speeches from the Australian Parliament is by using the ParlInfo search function on the Australian Parliament House website. ParlInfo allows you to search for documents from a number of sources including Hansard. Hansard is the written record of what was said in the parliament, including all speeches on bills
If you need to search for other legal texts such as bills, laws or explanatory memoranda the APH site has links to other relevant legal databases here.