Get friend list and group list by REST API or Javascript SDK

Hi everyone, I have some problems when I integrate Kakao API (or Javascript SDK) with my app.
1. How I can get a friend list?
2. how I can get a group list?
are the two problems above free to call?
I have researched that I need to register for a Biz app, but I can’t register for it
Could you guys help me explain it? Thanks all

Hi~
Would you like to check the contents below first?

Checklist to use the Messaging API and the Retrieving list of friends API