A very basic intro to installing the NVMe Base under a Raspberry Pi 5.
https://shop.pimoroni.com/products/nvme-base
Make sure your eeprom firmware is up to date with the 2023-12-06 or later version. Software update on the RPi OS should do this for you, but you can force it by running 'sudo rpi-eeprom-update' in the Terminal.
If you want to try PCIe Gen 3 speeds you can add this line to the [all] section of your /boot/config.txt
[all]
dtparam=pciex1_gen=3
If you have updated your firmware and want to boot from the NVMe drive, you might have to get technical and run 'sudo rpi-eeprom-config --edit' from the Terminal and change the BOOT_ORDER to be 0x416 instead of 0x41.