Need to share an unmanaged switch between 2 different LANs
I have got IP Cameras installed in my building and I installed an unmanaged PoE switch for them. I want to share access to the cameras with my neighbours who are getting internet from the same ISP as me.
From what I know and researched over the past 2 days I am thinking of this setup:
Unmanaged Switch(With IP Cameras connected to it) -> Managed Switch -> Both LANs
I am planning to get a managed switch for this but confused on what to look for.
Also I can't replace the unmanaged switch with a managed switch as it would increase the budget and I am trying to avoid it. I am not sure but I believe that if I connect both networks without proper isolation from each other it might create a loop and end up creating more issues so what do I need to check before getting a managed switch (other than VLAN capability which every L3 switch has)? Also will my setup work or am I overlooking anything?
More details->
I need to share cameras on both networks because both LANs will be running Home Assistant Server. I thought about installing a router instead of the managed switch but it just feels redundant as I would only be using VLANs(I think?) and that can be done with managed switch too. Currently my network is connected directly to the unmanaged switch and I assigned static IP to the cameras in 192.168.68.0/24 subnet which is what I am using in my network, my neighbours haven't connected yet. I have connected the unmanaged switch to a managed switch in my network so there is a possibiility for me to setup VLAN for my network to isolate it, if required.