Thank you very much for your feedback. Currently we do have a CLI utility tool inside Golang repository. On how to get started please check readme file. If you don’t feel like compiling from source and just want to use CLI I will build a release version today so you will be able to download it and use it. If you will have any issues please don’t hesitate to ask.
Since Zeebe is intended for high performance we do not provide REST API at this stage. Yes, we currently only support Java and Golang and support for other languages should come eventually.
For Java there is a awesome getting started guide here or if you want to get started with go I would recommend you checkout example microservice here.
If you still have problems with getting started, feel free to ask more specific questions. We are always glad to help.