[Soliloquy]

yes, for canning they should be ripe. For baking, you could use under-ripe but you won't have the same flavor. Pears are ripe when they barely respond to pressure at the neck. They turn to mush pretty quickly if not consumed or preserved after that. https://usapears.org/pear-ripening-and-handling/

Basics of water bath canning https://www.freshpreserving.com/waterbath-canning.html (You wouldn't need a bubble freer. That's needed for thicker substances like jam.)