how do I update ios software past 12.5.5 on my Ipad

Have you gone to settings an then to General am look for software update it should let you update to the new update if you haven’t updated in a minute. Do you have a old device like the 1gen or 2 gen or 3 gen then no you can’t update it’s time for a a upgrade instead it’s good to upgrade every 4-5 years or 6 years before your device no longer able to update to a better update cause old software can’t support the big update an futures that’s it comes with the newer updates

If your device is running 12.5.5 it is too old to run anything newer.