non-technical? Means they don't know how to use a computer or install and configure software.  That is a tough one.

-What guides?
    I'd say find a friend or family member who you trust and knows about bitcoin and their way around a computer.

   Find a trusted tutor to teach you the ins and outs of Bitcoin.

-Where to buy?
   Always without exception no-kyc.
   Bisq.Network - complicated P2P trading not for beginners.
   Robosats.com - very simple P2P trading using lightning and Tor Browser
  
   Need a dedicated bank account for fiat/BTC transactions only. Bank will freeze your account if they discover what you are doing.  Tell them transactions are for services rendered.

-How to store it?
  I prefer my own cold storage solution but worst case buy one of the devices online.  Be aware these companies that you buy your device from will sell you out to the government if it every comes to that.