Destroying your printer is a little extreme in my opinion. As long as the printer is still in your possession, you can be comfortable. In fact the older the printer, probably the better. There's just a chance that on some newer printers, printed files are stored in memory or HD. So to be entirely sure, don't give the printer away if you still have funds stored on the wallets printed by it. If you get a new printer and want to dispose of the old one, then destroy it.
Even better, don't use a printer at all. Just write out the mnemonic seed, that's what it's for.
Plus I have no idea how many viruses/malware I might have on my computer because it's a pretty old one that has seen better days.. (2005-2006ish XP).
This is the more important thing. If you boot from a live CD such as Tails to generate a cold storage wallet, you can be certain no malware is monitoring your activity, and no data is being stored on persistent media (HDD).
Well I just bought a cheap USB that I was going to download Ubuntu too and upload that as my new operating system, but maybe if I just test it out first and the first thing I do is go on moneroaddress, disconnect from the Internet, then write down everything and store it away I'll be good?