You should notice that whenever you add new contacts on your phone then you are provided with options to save contacts on phone memory, Google account, or SIM card. Note- You will get the option of a Google account when you are already signed in to your Google on the phone. Follow the steps to save contacts on phone:
1. Go to the Contacts app and then click on Add Contacts.
2. Now on your Android phone, the default storage is if SIM card then clicks on SIM card. Then select the location where you want to save your contacts.
3. If already contacts are saved on SIM and you wish to move them to phone memory or Google account then you have to import contacts from the SIM card to the device.
4. Simply go to the Contacts app, click on More> Settings> Import/Export contacts > Import > Import contacts from SIM card > Save contacts to Google device / other account