I am new to MapR community and started with DA450, Can you please suggest me how and from where we need to install sandbox.
The sandbox to do DA450, as well as most other trainings can be found here. I recommend you download the one with Drill if you can, as it can be used for Drill training as well.
The sandbox works very well with VirtualBox, which can be freely downloaded from here. Make sure you can allocate at least 8GB ram to the virtual machine. The performance will be fine, I was able to complete all the trainings with the default settings without any problems on my Macbook Pro.
Useful tip: Don't login directly from the running VM, you can login from the terminal (or PuTTy if you are on Windows) using normal ssh to localhost on port 2222 with user "mapr" and password "mapr" (root is also available with password "mapr"):
> ssh -p 2222 mapr@localhost
Retrieving data ...