Kontakt Free player doesn’t come with sounds that I know of. You can probably search for a number of free sounds and libraries that work in it.
Usually anything you might buy directly from Native Instruments will work in the free player.
As for third party Kontakt libraries, be careful when you buy. Most will probably work with the free player, but some do exist that REQUIRE the full version. So, check the description of third party Kontakt libraries before buying. They should state if they will work in the free player.
Unless things have changed since I last looked, Kontakt’s ecosystem requires sound designers to register and get special permission for their sounds to work in the ‘free player’. Sometimes you might find sounds or libraries for Kontakt that only work in the full player…as the sound designer opted NOT to go through the process to make it work in the free player.
Steinberg’s HALion platform is a little different in this respect. Designers who make sounds/libraries using the full HALion 7 version always have an option of rolling a library that can work in the free HALion Sonic 7 player. We don’t need special permission, keys, or to pay fees to Steinberg to make it compatible with the free version of HALion Sonic. It’s simply a matter of designing to a template that is ‘compatible’ with Sonic, making sure the vstpresets are saved/tagged as Sonic compatible, and that all the samples and other bits needed are part of the library (or post requirements of any supplemental libraries where samples and stuff come from that are required to make it all work. I.E. if I make a bank of FM Lab presets to share, end users will need to own the FM Lab library and have it installed. If I use a bunch of samples from HALion Symphonic Orchestra, end users will need to own that one and have it installed. If I only use my own samples/scripts/macro editors, and pack it all in the library, it’s good to go for anyone with Sonic, and target users require nothing else to get it working).
As for the nomenclature of the HALion platform, it works like this.
HALion Sonic 7 - Comes with most if not all Steinberg hosts. Cubase, Nuendo, Dorico, etc. The hosts usually come with several sound libraries that can work in the player (At a minimum you get a set of General MIDI sounds, plus a little). The different hosts and their respective levels (Elements, Artist, Pro, etc) might come with more or different libraries than others.
HALion Sonic 7 can also be downloaded all by itself, to work in any VST3/AU/AAX host. This download does NOT come with any sound libraries at all. The license for this player doesn’t unlock any protected libraries on its own. It can play unprotected libraries, or libraries that you have purchased keys for (registered on eLicenser or Steinberg Activation Center).
HALion Sonic 7 Collections - This version can be purchased, and it comes with several libraries. You get thousands of sounds!
HALion 7 - The full developer set! HALion 7 comes with all the libraries in Collections, plus some legacy stuff going all the way back to HALion 4. It’s possible to import the content from even older versions of HALion (hunt it down and install it…the H7 key unlocks it). It is a full HALion development package. You can deep edit most existing sounds (portions of some libraries might have locked layers that can’t be deep edited), and make your own entirely from scratch. It has everything you need to craft sample/synth zones and layers, add lua scripts, design arp/pattern players, make macro edit pages, pack libraries for distribution, and more.