As other said, consider Debian 13/trixie (the current stable), because Debian 12/bookworm no longer receives security updates.[1,2]. Regarding an installation with a thumbdrive, i) be sure that it is active during the booting process which may require to edit the sequence of priorities of devices from which the computer boots (hard drive, optical drive, usb, etc). Often it is by simultaneous touch of keys `Ctrl` and `F2` (or `F12`) at one stage of the normal boot process that this can be halted; best if you can read the documentation of the computer / previous operating system.
If you want to opt-in for using a spare thumbdrive, I recommend the freely available [rufus] to prepare the stick. This comes handy to check if a hardware is compatible with the Linux version, or running the Linux from the thumbdrive without permanent installation (live iso session) on the computer in question though generally a bit slower than a real installation on the computer. For elder hardware (10 years and above), I sometimes observe current USB thumbdrives fail in the process; often, this can be resolved by equally using an elder USB key (of USB 2.0 protocol, as purchased in the 2010s) instead of one running by the USB 3.0 protocol. Regarding user groups, both [GTALUG] and [Toronto Ubuntu Meetup] appear as suitable venues. Best regards, Norwid [1]: https://www.debian.org/releases/ [2]: https://endoflife.date/debian [rufus]: https://rufus.ie/ [GTALUG]: https://www.gtalug.org/ [Toronto Ubuntu Meetup]: https://www.meetup.com/ubuntu-linux-toronto-meetup/events/316664124/
