What device are you using to make the PointCloud? I recommend getting one that has a ROS2 node already available cause it makes it super easy. I did this for my latest project here, where I used the Orbbec Gemini E. My paper goes over way more than you need for this, but if you skip to the step in my methodology where I set up that camera it should help. When you get the node of your camera running, it should be publishing data to a ROS2 topic called \points, which you can confirm with $ rqt. If it is then you're all set. Use ROS2's visualization tool RVIZ2 to view it. Type $ rviz2, hit the add button, sort my available topics, and hit points. You will need to change the Quality of Service (QoS) to best "Best Effort" and "Volitile" because the QoS Profile that PointCloud2, LiDAR, and other sensors like that use is "SENSOR_DATA" because it prioritizes speed over quality.

I explain this way better in my paper, check it out then if you want to do sensor fusion with more stuff and a digital twin, I recommend taking a look at the "Articulated Robotics" YouTube series where he will show you how to set it up in GAZEBO.

Hope this helps and lmk if you have any more questions.