Claims for beginners

OK tips much appreciated. I'm completely new, but have settled in. Found copper and iron, and now want to settle down permanently.
This is obviously a big decision. I have read all the guides I could find. Still Im feeling unsure, so here's a few questions:
1. Is it correct to assume any structure left in the open belongs to nobody. Everybody can take everything. This is how it seems to work, when I find abandoned camps (although in respect I have taken not a single item).
2. If so, then I need to make a claim to put my storage / structures inside the claim. To protect it against simple theft.
3. And when placing a claim you thereby also prevent others from entering (law abiding people anyway).
4. So to protect my new iron mine, I must put down a claim around it, for safety reasons?
5. Since I already make one claim, with my few humble belongings. Can I make another for 150s. Or how does that work out?
6. I have found a nice spot with access to grass/forest/iron mine/copper mine/clay and a small lake. All in the same mini-map. Will it hurt me, that the body of water is rather small (beavers? fish?)
Other tips, if you have any to share, which seems relevant, right here?
Thanks in advance.
This is obviously a big decision. I have read all the guides I could find. Still Im feeling unsure, so here's a few questions:
1. Is it correct to assume any structure left in the open belongs to nobody. Everybody can take everything. This is how it seems to work, when I find abandoned camps (although in respect I have taken not a single item).
2. If so, then I need to make a claim to put my storage / structures inside the claim. To protect it against simple theft.
3. And when placing a claim you thereby also prevent others from entering (law abiding people anyway).
4. So to protect my new iron mine, I must put down a claim around it, for safety reasons?
5. Since I already make one claim, with my few humble belongings. Can I make another for 150s. Or how does that work out?
6. I have found a nice spot with access to grass/forest/iron mine/copper mine/clay and a small lake. All in the same mini-map. Will it hurt me, that the body of water is rather small (beavers? fish?)
Other tips, if you have any to share, which seems relevant, right here?
Thanks in advance.