You have to be a server admin to create a channel. If you don’t have administrator privileges, you won’t see the “+” icon here.
If you don’t have any contacts on this server, this option will appear as @everyone.
If you create a text channel, Discord will automatically open your channel on your screen after you tap the white floppy disk icon. If you create a voice channel, Discord will open your navigation menu after you tap the white floppy disk icon. Tap on your channel name under the VOICE CHANNELS heading to access your voice channel.