after installing arch I'm met with a grub prompt and nothing else

I had that too when I first installed arch. Iirc you have to grub-mkconfig -o /boot/grub.conf (don't quote me on that, check the wiki). I think you can just boot the liveiso and chroot into your system to do that, no need to reinstall.

Might be that you didn't install intel-ucode or amd-ucode.

Did you use btrfs ? Did you encrypt with luks ? Because if so, you have to add the hooks to /etc/mkinitcpio.conf.

If you didn't encrypt your drive or use btrfs, have you installed GRUB beforehands ? Because that screen might be from your old GRUB. If so, you need to install GRUB.

If so, reboot to your liveISO. Mount /, mount /boot then do :

arch-chroot

grub-mkconfig -o /boot/grub/grub.cfg

grub-install --target=x86_64-efi --efi-directory=esp --bootloader-id=GRUB

If that does not make sense or you need help figuring out, just reply to the comment. Arch is hard to install the first time. It often takes several tries to get it right. It becomes easy the second time round.

Try typing "exit" and hit enter. I have a dual boot laptop that defaults to this screen every reboot.

I think you have to use grub-mkconfig -o /boot/grub/grub.cfg to generate the boot entries in grub. I just installed Arch on my Surface Go 2 following the wiki, and I also missed that at first. You can do that by using arch-chroot after mounting the root and boot partition following the wiki.