Tailscale raspbeery pi


I am a new user in tailscale and nothing know about tailscale network config. I am going to setup a raspberry pi and make it a subnet router for all of my devices to be connected to at my home in a censored country then buy a VPS outside my country as exit node to be able access to web for all devices freely.
as said on the website it is not necessary required to install tailscale on each device which is good for my case, but I don’t know the step to step instruction from a2z to setup the raspberry pi as a subnet router . one important thing is, when I add a raspberry pi subnet router in my home, I should have two distinct wifi signals, wifi signal 1 from my existing router and wifi signal 2 from the raspberry pi, since I must use my existing router to browse local websites, online banking and local online shopping and with VPN can’t do these things access from abroad is blocked to local websites and use wifi signal 2 only as VPN to run blocked apps and browse websites.
is there the detail instruction enables me setup a raspberry pi subnet router by myself easily.