How to install NAV/BC with a demo database?

Hi Experts,

I used to work on Navision 4.0, 5.0 and 2009 two years> During this time, I have been using the classic database. I left Navsion for 5 years and now I want to go back to it. I undertand the classic version is discontinued. Now I am trying to install the RTC in a demo database so that I can start learning, but I don't even find the installation file and how to install the RTC client in a demo database for learning. Can anyone help me on how to get the software and how to install it for learning purpose?

(Subject changed by admin, was: How to install RTC with a demo database?)