Based upon using my own (Alcatel) phone:
1. If go to 'Contacts', rather than the phone icon, when you want to make a call, you can select the contact you want and then press the 'call' button.
Alternatively, if you do select the phone icon, type part of the person's name in the 'number' field and you'll be offered a list of all matching contacts to select from.
2. Purpose-made ringtones are now largely a thing of the past. That's because smartphones can usually use any MP3 file that's within it's 'Music' folder as its ring tone. Put an MP3 file of your choosing in the 'Music' folder and then, when selecting a ringtone, look for 'Other' (or something similar). That should then provide you with the option to select the file you want from your 'Music' folder.
3. I'm not sure about the icons you're seeing but, in general, you can leave the 'wifi' function turned on most of the time. (The only exception might be where you've used a pub or store's wi-fi in the past but, for some reason, your phone can't reconnect when you visit there again. You'll then need to turn the wifi off to persuade your phone to use the 3G/4G/5G network that it connects to when you're outdoors).