Hey, @Evie42548. The ssh and wpa_supplicant.conf files will be removed from the boot directory - this is normal. When you power-on, Raspbian looks in that directory and uses the information from the files, then cleans them up.
Have you tried the troubleshooting section? You may just have to try connecting to raspberrypi.local.
Best of luck! Let us know how it goes.
