How to create a Wireless RF circuit activated by an ultrasonic sensor for interesting project?

Yes, I will be using waterproof materials and designing it in Fusion 360 when I know what components I will be using, so I can design and build an enclosure around all the parts. Have just ordered some IR sensor modules and a couple of Arduino Nanos as well as some 433MHz RF wireless transmitter/receiver modules, which I will play around with tomorrow and see if I can learn how to code it all together using the libraries for reference. Not great with coding, so I may be pulling my hair out lol!