OK, well after days of search toptics and basic tutorials…
immediatly after posting this I found this:[OH3] Tasmota via MQTT Autodiscovery
which told me to setup auto discovery on the tasmota (I though auto discovery when the other way;)
it showed up in openHAB and my sensor readings work.
I had some configurations mixed up. Ill try to sort it out and post my errors;)