SD cards wont ever fit the RPi4B's slot
You need a microSD card... the most recommended card rating as A1. Am currently using 16GB on this RPi4B-4G Desktop setup.
as the 4GB unit... I dont need to enable the swap file, there is plenty of RAM to go about my usual use-case.
if you enable swap... you risk shortening the life of the microSD card
if you still want a swap... better attach another drive and use a space (not all) in that drive as swap.
if you still want to use SD cards.... you need an SD card to microSD adapter.