Hi @AmandaOneill welcome to the /e/ forum. It is likely the first problem was due to “timing” of the reboot into TWRP for the first time: Know your hardware - Samsung.
For the bootloop, please can you try to “catch the moment” in the bootloop and use accurately timed button presses of Volume Down + Home + Power to try boot into Download mode. When lucky, you can just try to flash TWRP again.
Bon chance. 