I want to connect aggregation db with mongo compass
Check this thread
When you connect to your db with Compass, open a collection, and then you will see “Aggregations” in the tabs below the collection name.
There you can visually create your pipeline but you also have a “mongosh” at the very bottom of app. To be efficient you need to learn how to write stages and pipelines.
I suggest you “not” use the Compass (nor mongosh in it) as your primary tool in this course. Just download command-line tools and work with it mainly and then try them on Compass and see differences. Some actions are better understood in the console and some better in Compass. make use of them both.