IntelliJ is without question a fantastic IDE, but learning how to work efficiently is not particularly easy for the beginner. However, it is very worthwhile to delve deeper into the functions and this includes shortcuts.
I am convinced that mice and trackpads are tools for graphic artists and designers, people who write and develop a lot should keep their hands on the keyboard if possible.
Shortcuts are always a complicated topic because what you want to use and what does not depends very much on your taste. Some like commenting at line level, others prefer to use block comments, and in professional projects, there are often requirements in the team or at the customer.
In addition, the shortcuts differ for each operating system (macOS, Linux, Windows) and the key combinations can be customized. Last but not least, the key combinations are also slightly different for each national keyboard layout, or they sometimes don’t work because they were only designed for a US keyboard layout. An example can be found here, this problem has existed since 2007.
Before I share my shortcuts, which I use the most, I would like to refer to the following two articles, which give very good insight, especially for beginners:
macOS shortcuts that I use in my daily work
One or the other may wonder about the arrangement of my compilation. Ultimately, with the key combinations, the special keys must be pressed at the same time and are then followed, for example, by a letter or a cursor key, etc.
Such lists often follow the logic that the combinations are ordered according to the special keys. For example, first SHIFT, then CTRL, then OPTION, then COMMAND. However, how best to memorize the key combinations is also individually different, so there is probably no way around the fact that everyone has to create their list.
Nevertheless, my list should serve as an “idea generator” and together with the articles mentioned above (even if they are older) give a good insight into how a solid IDE can make your daily life much easier.