Hello
My name is George Botsaris , I’m from Greece and I start using Mongo DB because I’m using an application that use Mongo DB.
I’m having development skills but using Sql Server and Oracle , So Mongo is something different to me.
I was wondering if there is any course that I can watch just to understand who Mongo works ?
Furthermore if anyone knows , is there any way to import and export data from Mongo.
In any case
Thanks a lot for reading my message . 
Hello @George_Botsaris and welcome to the MongoDB community!
MongoDB has several free courses that will help you learn to use the database.
I would recommend the following as starters:
As for importing and exporting data, you can look at the mongoimport and mongoexport commands.
These two courses, and the documentation, should help you get started on your journey. As you work through things, the community is here to help you out and answer your questions.