How to connect an outdoor camera? LAN, power or battery

Alternatively, I could probably work with Blink xt2 and attach them to the rain gutters at the front and back. However, I would prefer to store it on my own server and not be solely dependent on batteries... Well, I hope someone else has tips.

Type into the web search: „Surveillance Floor Planner“.

First, define what you want to see with the camera. You don't need to think about positions beforehand at all! After that, you think about the camera (design, resolution, focal length, night vision/range, etc.) and THEN you decide where and how many to install sensibly. If you do it in a different order or if a factor is fixed on site, it will either be more expensive (camera selection possibly limited because position and area to be monitored have already been determined, requiring special solutions like fisheye or 360° cameras) or it won't work (you don't see what you want to see because you have a camera that doesn't fit the chosen position).

That would mean, if our camera at work breaks, we could only buy the same one and if that no longer existed, simply none at all.

No, you only need a camera with the same field of view, meaning the lens type and focal length should match. That determines whether you can see what you want at the given position.

Ok, so the most important thing for me would be to monitor the garden area for burglary protection. Therefore, I wonder whether mounting the camera higher up is actually beneficial. Otherwise, in the worst case, you only see "dark figures." Positioned a little above head height facing the terrace might be better. The second camera also serves burglary protection and is intended to observe the area around the garage (climbing aid for the first floor). Night vision and motion detection should be possible with the camera. The recording should also have good quality.

Try typing in the web search: "Surveillance Floor Planner."

But that is only for companies, am I right?

Then the positions aren't that bad at all. Towards the garden, I would mount it about floor level on the upper floor, for the garage 1-2 m higher, otherwise you'll just be lighting up the garage wall. Use something with a maximum focal length of 2.8mm and at least Full-HD resolution. I would currently even record in 4K, storage hardly costs anything. Especially at night, nothing helps more than resolution and a good lens. Of course from a good camera and not with <100€ cheap stuff. Hikvision Turret for example, they have really good night vision with proper IR light. By the way: No burglar is deterred by cameras.