You'll need to post a bit more info if you want help. Are you just joining 48? If so did you activate the SIM? If you do a scan for networks can you see and connect to 48? Is your phone unlocked for use on any network? What settings are you referring to above? If necessary contact 48 support. See the link in my signature below.
Hope this helps.
I am not a 48 employee so if you need to contact 48 support then use option 3 or the chat facility here.