I am not an accountant, so unlike many property gurus I am not going to try give you a bunch of tax advice.
This is merely a prompt that it is now time for you to reach out to an accountant if you haven't already as part of purchase process (see Step 2) - there are plenty of tax strategies you can implement as a landlord and things you need to track in order to make your life easier come tax return time and you should talk to an accountant about this.
You should also reach out to a quantity surveyor who can get a depreciation schedule done for you (if your property is eligible), this is related to certain tax deductions you can claim - ask your accountant about this.
There is also plenty of content on the internet, such as the following videos.