ASTRID is available on GitHub at https://github.com/pranjalv123/ASTRID. In particular, you should download the appropriate executable (ASTRID-linux or ASTRID-osx) from https://github.com/pranjalv123/ASTRID/releases, as well as test.zip, which contains example datasets that we will use for the tutorial. No further installation is necessary to use ASTRID.
Additionally, it will be useful, but not necessary, to have Java installed on your computer (https://java.com/). The current version of ASTRID does not support Windows, but I will be able to accomodate some Windows users on a remote server - please contact me before the tutorial if you're interested in this.
Feel free to contact me (firstname.lastname@example.org) if you have any questions about running ASTRID, or if you're having trouble downloading or running it.