Hyper-V internal switch and VM OS interfacing with Guest OS and IP Cofiguration
NOT AT ALL - it is a switch, like any switch you have in your network rack.
Access internet in guest os
Set it up so that the quest gets an IP address from the internet router and the internet router does NAT (which it quite obviously already does).
seemlessly share files & folders between guest and host OS.
You mean like any of the hundreds of thousands or millions of networks do?
Thing is simple - make sure that the routing and or Switching layer works and is set up in a sensible way. Hyper-V is totally the same as any other physical set of computers.
Apart from physical lan adapter (say adapter 1), I see another LAN adapter (say adapter 2) added in host os.
Yes, and if you explore them you see NO binding in adapter 1 except the switch, and all binding on Adapter 2. If the whole thing is set up as a proper network (not internal or private) then a VM starting will be seen as a different physical machine and the router you have will / should give it an IP address.
What is the best way to configure IP of these three adapters
Define BEST way. Normally the answer is "not at all" or "static". not at all means that your router or whatever will use DHCP on all machines, static means you dont rely on the router (due to IPv4 being so stupid to not distribute IP addresses AFTER start, other than IPV6, so if the router i off when servers star, they dont pick up IP addresses).