Eclipse vs GitHub Enterprise

UPDATE: Thanks for the great response. I am going to start with VSCode based on the open source and free version that will allow me to grow into other languages, but not cost me a license ..yet.

I have been working with software development for 12 years, but I am just beginning my journey to learn to code. I am starting with Python following the suggestion of some of my coworkers. They are split between Eclipse and IntelliJ IDEA for IDEs that they use and PyCharm is new to me. Which IDE would you suggest for a beginner that will allow expansion to Java, JavaScript, and eventually AngularJS and possibly mobile applications?

I originally chose IntelliJ over Eclipse, as it was close enough to the look and feel of Visual Studio and we do go back and forth between the two. We really begin to love IntelliJ and their suite of IDEs so we are now using AppCode for the IOS development because the workflow is identical with the IntelliJ. IntelliJ is super complex and intimidating at first but it does afford a lot of nice utilities to get us produce clean code.

We are using a Bitbucket server, and due to migration efforts and new Atlassian community license changes, we need to move to a new self-hosted solution. The new data-center license for Atlassian, available in February, will be community provisioned (free). Along with that community license, other technologies will be coming with it (Crucible, Confluence, and Jira). Is there value in a paid-for license to get the GitHub Enterprise? Are the tools that come with it worth the cost?

I know it is about $20 per 10 seats, and we have about 300 users. Have other convertees to Microsoft's tools found it easy to do a migration? Is the toolset that much more beneficial to the free suite that one can get from Atlassian?

So far, free seems to be the winner, and the familiarization with Atlassian implementation and maintenance is understood. Going to GitHub, are there any distinct challenges to be found or any perks to be attained?