Can you set an iPhone from blocking callers?

Go Into the store where you bought the Phone and they can help you . Apple is Usually Pretty good .

Yes, if you cant figure it out go to YouTube, put in you phone make and model, they will show you step by step how to do it on your phone.

I do it all the time for anything, my car has so many gadgets that I can't figure out, I found YouTube to be the most helpful, and you can pause it and rewind it .

Like I would go to YouTube, put in how to block calls on my Samsung, then the model. It's so easy and so helpful, and a great learning tool for all of us computer illiterates.

Good luck

Block voice calls, FaceTime calls, and messages from certain people in the Phone app , Tap Favorites, Recents, or Voicemail. Tap next to the number or contact you want to block, scroll down, then tap Block this Caller.

Send unknown and spam callers to voicemail:
Go to Settings 
 > Phone, then tap any of the following:
Silence Unknown Callers: You get notifications for calls from people in your contacts, recent outgoing calls, and Siri Suggestions.
Call Blocking & Identification: Turn on Silence Junk Callers (available with certain carriers) to silence calls identified by your carrier as potential spam or fraud.

Source: https://support.apple.com/guide/iphone/block-or-avoid-unwanted-calls-iphe4b3f7823/ios#:~:text=Block%20voice%20calls%2C%20FaceTime%20calls,Favorites%2C%20Recents%2C%20or%20Voicemail.&text=next%20to%20the%20number%20or,then%20tap%20Block%20this%20Caller.

yes!

Yes, but you need to add the specific phone numbers. If you want someone to be able to call out but not have to answer calls, you could always put it on mute.