How do I set up VLANS to be available on all ports but only usable to those on the same VLAN?

I am using a TPLink smart switch and I am trying to setup dual WANs, each with their own DHCP service, coming into ports 1 and 2. I then would like any clients on ports 3-8 to be able to access either of the WANs by joining that specifics WANs VLAN, 20 or 23. I had assumed I could just set the PVID and then set that same ID on the Windows PCs but I cant figure out the combination of VLAN tagged or untagged ports or what is needed to do this.

Do all ports need to be in both VLANs? Should they be tagged or untagged for both? I have tried both way and what I have seen is even if I do not set the same VLAN on the PCs they are still picking up the IPs from the WANs so how do I stop that when the PCs are on the default VLAN and not on VLAN 20 or 23?

Any help appreciated. Thanks

This is my router setup... https://i.imgur.com/cE8CpvS.png