You only need:
- a smart phone, computer or tablet;
- a credit card; and
- 5 minutes.
The design registration will prevent your product being copied for up to 15 years.
Suggestion: Also mark your drawings and marketing material with the copyright symbol ©, your name and the year (e.g. © 3D Copyright, 2018). You may add the copyright symbol irrespective whether you file a design registration.