A usb mouse (an el-cheapo, "travel" one with a reel for the cable is good enough)[1].
If you have space enough I would also consider a (small) USB keyboard.
Anecdata:
only three days ago I was working on a (relatively) important document on a (crappy) Windows 10 laptop. I had not saved the work and went to lunch (I know I should have saved it) leaving the document open in the word processor. When back, for whatever reasons, the computer trackpad and keyboard did not respond. Luckily I had a spare mouse handy and managed to save the document before rebooting and "fixing" the issue. Actually I don't think I fixed anything, upon reboot the keyboard worked just fine, but not the trackpad and had to re-install the trackpad driver.
I had this same thing happen a couple other times on older Windows laptops.
[1] I have one of these cheap kits, that include a small USB hub and various connectors beside the mouse:
Anecdata:
only three days ago I was working on a (relatively) important document on a (crappy) Windows 10 laptop. I had not saved the work and went to lunch (I know I should have saved it) leaving the document open in the word processor. When back, for whatever reasons, the computer trackpad and keyboard did not respond. Luckily I had a spare mouse handy and managed to save the document before rebooting and "fixing" the issue. Actually I don't think I fixed anything, upon reboot the keyboard worked just fine, but not the trackpad and had to re-install the trackpad driver. I had this same thing happen a couple other times on older Windows laptops.
[1] I have one of these cheap kits, that include a small USB hub and various connectors beside the mouse:
https://www.tradeshopitalia.com/accessori-usb/177-kit-usb-17...
This is an old one, nowadays you would need also some USB-C converters/adapters.