Thanks for including my (sic) into your email – there is a link at the top & bottom of the email you received which will allow you to unsubscribe from all Liberal updates.
In regards to your question, the only information the Liberal Party would have on you is the information provided by the Electoral Commission ie. your names and address, which is publicly available. I believe you can apply to have your details suppressed – and have included a link where you can check on your details and make changes: https://oevf.aec.gov.au/ <https://oevf.aec.gov.au/>
I hope this helps,