When I first setup my 2 Umbrel nodes, originally RPIs with 4GB + 2 TB SSD & 8GB + 1TB SSD respectively, I used the Lightning node itself to open channels using https://amboss.space/ and https://lightningnetwork.plus/ to find suitable nodes.

This was easy and cheap at the time. I remember setting up several triangle nodes to small capacity nodes on my first Umbrel and several large capacity channels to large public nodes on my second Umbrel. I also setup large channels between my own two nodes so I could route payments across my own network. I was experimenting heavily.

To rebalance, I installed RTL, Ride the Lightning and Thunderhub, but quickly realised that RTL was the tool for me. I also installed an auto rebalancing tool called LNDg, which I spent many months watching YouTube videos and reading articles in a failed attempt to master.