Looks like you have not fully understood how the BLE API works. The available characteristics are pure input/output pipes. i.e. you send a data stream there and get a response back.
There is no characteristic from which you can read the state. You need to send a “get state” command to the lock and will get a response back. Because everything that is sent is encrypted you first need to pair and create an authentication which allows you to send encrypted commands. There are detailed examples at the end of the BLE API specification for pairing and sending commands.
It might be useful to have a look at other implementations using the BLE API in order to help you understand how it works.