I only recently got Ardour and am still trying to learn to ropes to it. I installed a drumkit sample (from here: http://www.themetalkickdrum.com/) and have no idea how to see it in the MIDI Instruments list when creating a new track, and also how to actually upload it. The file is downloaded as a .zip folder, and when extracted it becomes a folder without a bunch of .wav sounds. I’ve found out how to import each individual sound into a track, but not how to set it up as a MIDI.
If I assume your intentions correctly (you want different drums to play on different keys), you could use the FOSS LV2 plugin, Fabla by OpenAV Productions. I found out about Fabla because it’s included in the lv2-plugins group of the Arch Linux repositories (which is a great resource if you’re trying to find good plugins that work well with Ardour).
Fabla’s custom plugin GUI has a 4x4 grid of configurable pads that accept MIDI input. On my actual physical MIDI controller/pads, I just use the “Pad Learn” feature to bind my pads to the appropriate MIDI keys (to be clear, “Pad Learn” is a feature of the hardware that I own). Then, I can just use my physical MIDI pads to lay out a beat while Ardour records the notes to Fabla’s MIDI track (including the velocity of my MIDI pads). It works quite well for my use case.
To get it setup in Ardour, you’ll first need to install it (this will vary, from system to system, but it should be available in most Linux distro’s default repositories, so it should be fairly simple). The next time you launch Ardour, it should actually attempt to locate your new plugins. Fabla should hopefully now be in the “Instruments” list when creating a new MIDI track. If it is not, you can manually scan for new plugins using the Plugin Manager under “Window” > “Plugin Manager”. The Plugin Manager is also super helpful for finding out why a plugin may not have loaded.
If you need further instruction (e.g. how to show custom GUI, configuring MIDI hardware, etc), the rest should mainly pertain to Ardour itself. In this case, Unfa makes fantastic videos on YouTube. He’s pretty much where I learned everything about Ardour. That and just playing around. You’ll get the hang of it, trust me