I used Ubuntu in my college for some light programming and felt really happy about it.
I am more interested in switching to Debian 12 than Ubuntu, since the former is really stable. Also, I came to know installing Debian is easier since it supports non free firmware.
I think my laptop is 7 or 8 years old. I have an HP printer which I use. Will my printer work ?
You’re almost certainly fine. Check the Live DVD, but I’d bet it works seamlessly.
HP actively supports their printers in Linux. Debian 12 is not listed though, only 11.
https://developers.hp.com/hp-linux-imaging-and-printing
Edit: Added the bit about Debian 12