When you connect a radio every node that connects shows up in a list.
Basically every radio functions as a repeater as well... so the more radios powered up, the better the network . Even better if they have decent antennas.
I have my shed antenna fully operational now, has been up for 3 days running on solar power, and I leave it up even if my client radio isn't on, just to benefit the community with an established base.
The other day I sent out a 'test message' in the general channel and received replies as close as 3km away (near Square One) and as far as the Distillery district in Toronto. I'm confident, based on the node list that I should be able to send a message to Oshawa from Mississauga, all without cellular or internet.
The general channel isn't encrypted, but any private channel you create is encrypted and you'll have to provide the key to whomever you wish to communicate with (QR code, or text or email the key).
Right now my home base is well setup. My shed repeater is always on with a decent 5.8dBi antenna raised 5m over the shed and is set up as a client_base, set to favor my client. My inside radio uses my base to communicate further distances.
I'm not overly impressed with the range of the stock antenna (2" dinky thing), so I have ordered a magnetic roof antenna for my car as well as some longer higher gain antennas just for the radio... all for when I'm away from my base station.
I think I am all in at $90 now... and I have two radios, 3 antennas, a bunch of adapters and cables; so it's a very affordable hobby if buying from places like aliexpress.
If anyone is in the GTA on meshtastic, send me a DM with your radio call sign and I'll see if I can make contact.