I have some experience writing queries and stored procedures in SQL server. I would like to learn how to use the Microsoft Business Intelligence tools (SSIS/SSAS/SSRS). There are loads of books, videos, and online courses out there to learn these tools (including free courses on the Microsoft website). My challenge is that I do not have access to a SQL server database with these tools. I see that one can download a free 'Express' version of SQL server from the Microsoft website, but this version does not have SSIS/SSRS/SSAS. Is there a free version of SQL server that has these tools--either a version one would download and install oneself, or an online environment with a full version of SQL server+BI tools that one could access for learning/practice purposes?
Evaluation Edition is Enterprise Edition with a timebomb (180 days). It includes SSIS, SSAS, SSRS, etc. So you can evaluate that for 180 days to learn the ins and outs of BI.
Developer Edition, also, provides these tools for ~$50-60 (Microsoft sells it direct for $59.95, though you may find it cheaper from other retailers). The difference is no timebomb but a vastly different EULA. (And if you have an MSDN subscription, you can get this edition - well, any edition - for free as part of your subscription. But there are still licensing restrictions on use, so please pay attention to the EULAs.)
There may also be ways to evaluate these features in the cloud, using Azure Virtual Machine images. I haven't done this, so I don't know if there's any way to take full advantage of this without incurring some level of cost, but I'm pretty sure you can sign up for a trial (I'm also pretty sure it will be significantly less than 180 days).
Also SQL Server Data Tools (SSDT) includes some additional features around building and maintaining solutions that might be useful.