Setting up Home Assistant using M.2 SATA SSD

Hello! I've just purchased my first Pi along with an Argon One case and an M.2 SATA SSD. I'm watching a video on the Home Assistant setup to get a bit of extra knowledge before they arrive and noticed I may be missing a couple of things... I don't have an M.2 SSD to USB adapter to install the Home Assistant OS using the Pi Imager - Will this be required, or can I install the OS on the PI itself? I also didn't purchase an SD card, the video I'm watching uses an SD card to install USB Boot so the OS will boot from the SSD instead of the SD card- Do I need to purchase a good SD card for this, or will the cheapest SD card I can find on Amazon be okay for this step? Thanks 🙂

Pi 4?