Which router for our new building?

It was just the idea to save costs for going to the studio if it gets too expensive.

Optimal, of course, all centrally connected to the poe switch

What would you say, is 1 access point per floor enough for us?
In the basement, should we also have an access point installed in the hallway or is it enough in the technical room?

??? and how do you connect the network to the access point? Each access point should/must have a cable. Take one access point per floor. In the basement hallway and in the technical room. The concrete walls completely absorb the signal. And one more for the garden.

Ok then we will place 1 access point in the hallway on each floor and on the back of the garage.

Which access point should we choose?
Unify is the best choice now, right?
Are the Unify nanoHD also suitable for outdoor use or do we have to use a different access point?

Different access point for outdoor. For example, FlexHD. With Unify, you can't go wrong.

Ok so unify is the first choice. Alternatively netgear or something.

I have never heard of unify until now.
Probably only known in specialist circles.

Which router and switch would you recommend to me?
If unify access point then also router and switch from unify right but which one?

I also use Unifi at our place (Accesspoint 6 lite). Setting it up was somewhat cumbersome, but now that everything is running, I am very satisfied. The price-performance ratio is definitely great with the lite models. Higher speeds usually fail anyway because of the end devices?! For the switch, I chose Cisco (350) because Unifi switches apparently have problems with Multicast Igmpv3 when watching TV. Unfortunately, the power consumption of the unit is very high, but otherwise, it is good.