Beginners in CS:GO may try to bring behavior patterns from other shooters, such as Battle Royale games – and this is not how to be better at CSGO. The game is not about just keeping alive and staying together to protect the team. Here you have straightforward goals, and you have to control the map to achieve them.
Of course, you should know the locations and behave as a team, so this tip is a sequence of the previous two.
Counter-Terrorists should focus on covering approaches to the bombsites and play patiently in defense. Terrorists should not only rush to a bombsite but also think about clearing the place and then protecting it from any enemies.