Can I add a custom item that I can place down in-game (with a custom 3d model)?

Hi, I'm wondering if it's possible through datapacks to be able to add a custom item that I can then place down in-game with a custom 3d model. I also wonder if it's possible to change the texture/version of an item once it's reached a certain stage after fulfilling a specific condition. Like for example, a wooden axe turning into a stick once it breaks instead of turning into nothing, that kind of thing. Is any of this possible through datapacks, or am I gonna have to make a mod instead? I'd really like to know. I've watched a few tutorials on how to make datapacks/how they work but I'm still quite the beginner and don't really understand how everything works yet. Any input is appreciated. Many thanks!