4. How to send the contact number by SMS? Why can't I view and save the contacts I sent?

The phone itself does not support inserting contacts or numbers into SMS. You need to do the following:

Main menu-Contacts-View Contacts to Send-Send Contacts (or menu key-Send Contacts)-Select messages to send-Contacts will be saved as vcf attachments in MMS and sent to the other party's mobile phone. If the other mobile phone supports this format, it can be saved. If the other party doesn't have a mobile phone, I suggest you send it in the following way.

Main menu-Contacts-View Contacts to Send-Edit Contacts-Press and hold the number to send and select Copy-then enter the phone message function and select Paste to send.