The 2012 Mini is no longer supported by current versions of MacOS, Catalina (introduced in 2019) is the newest version it can run. Catalina will most likely stop receiving security updates by the end of this year. Games don't interest me, but the HD4000 GPU in the 2012 Mini is definitely older technology and might be an issue. Wordprocessing and YouTube should be ok. I don't use Apple Music, but guess it would be OK although you may need to update to Catalina if the machine already doesn't have it installed.
The 2014 Mini is still supported by current versions of MacOS (AFAIK) but this year is considered a low point by a number of people who follow the Mini. The top-spec 2012 quad-core 2.6ghz i7 Mini is 50% faster than the top-spec 2014 3.0ghz i7 Mini, for example. Apple did not offer a quad-core Mini in 2014.
The base 1.4ghz 2014 Mini should definitely be avoided, I have one and performance is horrible. For example, just clicking on System Preferences would take about 40 seconds before it opened. Installing an internal SSD will help, but memory is NOT upgradeable on the 2014 Mini and 4gb really isn't enough. The 2012 Mini was designed with user-upgradeable memory (just twist open the bottom cover) and can be upgraded to a max of 16gb.
Frankly, I wouldn't really recommend either the 2012 or 2014 Mini (although I have both myself). They are just getting too old. If you want an Intel CPU, the 2018 is the only way to go, the base model will be much faster than any ofd the 2012 or 2014 Mini's and it will be supported much longer.