Im also brand new to ROS and Robot simulations. Honestly its kind of overwhelming how many sims are out there now. Gazebo, Webots, MuJoco, IssacSim, Drake, PyBullet .
When it comes to choosing a sim:
If someone already has a comfort level with a sim, id say stick with that and start building your project.
That said, It seems to me from a completely newbie perspective that Gazebo has the most tutorials that relate directly with ROS but in some cases may be not be as advanced.
The others seem to have more advanced capability in terms of physics models and GPU integrations for AI training.
The other thing to consider is if you are trying to follow some existing work/ research/ open source project , it may be wise to adopt / learn which ever simulator is used. Seems to me ROS has integrations for most of the above mentioned sims.
All this sim-to-real stuff is so bleeding edge I dont really think there is one robot viz/simulation platform that has come to the surface as the industry standard.