Need some beginner instructions - MIDI and Chromebook

[Watchman]

I last involved myself in digital music production in the late 1990s. At that time sequencing had moved to PCs and Macs but we were still using MIDI to control our (older) keyboards (and vice versa - using the keyboards to create sequences). The MIDI interface was commonly found onboard sound cards.

Now the MIDI interface is largely through USB (which is excellent) so I've bought a cable to link my daughter's keyboard to her Chromebook. They're very cheap (under a tenner) and it should turn up tomorrow.

What else to I need? I am assuming the Chromebook will recognise the interface - I have been surprised just how compatible it has been with everything I've plugged into it - so I'm going to need some sequencing software. Any recommendations for a free one?

What about sounds? Her keyboard is a nice keyboard (Yamaha) but the onboard sounds are rubbish - they're tinny, thin-sounding. It'd be better to download or access a library of "fatter" sounds to the Chromebook and trigger them via MIDI. Will there be any sounds abailable with the sequencer software, or are there packs we can access?

Just need to bring myself up to date with the capabilities and options - any help would be gratefully accepted.