I have installed ubuntu server version 17.04 on a desktop. I want to install inspircd 2.0.24 on the server and I have it on a thumbdrive..what is the command to tell linux to get it off there and install it?
If you require version 2.0.24 you can download the deb package from this link, and then choose to install it with your favorite package manager. You have a number of options. For example, you can choose to open it with the software center (although you likely don't have a GUI installed on your server),
gdebi or install it with
sudo dpkg -i packagename as indicated by @mariaczi above.
I prefer gdebi for local .deb installation as gdebi lets you install a local deb package resolving and installing its dependencies. apt does the same, but only for remote (http, ftp) located packages.
To use gdebi, (recommended) install it if you don't have it with
sudo apt install gdebi
Navigate to the folder containing the package and then install the desired package with
gdebi will notify you if the package isn't installable due to conflicts or unsatisfiable dependencies which should save you from any unintended consequences.
If you don't know where to find it, you can download a fresh copy from the link provided above or use
find which is explained nicely here.
If you have it as deb packages you can install it using "dpkg -i /path/to/the/package", but remember to install all required/dependency packages.