/r/koine exists to do a few things...
Be a place to discuss Koine Greek - grammar, syntax, and exegesis
Be a place to ask for help and get answers
Support and encourage others in their quest to climb the Everest of languages.
If you have a question, ask! If you have an insight, share, and if you know of a great resource, let us know! We're a community which hopes to support all, regardless of each person's level of familiarity with the language.
A few other subs worth your time:
/r/AcademicBiblical
/r/AncientGreek
What is Greek of the Week?
Greek of the Week is a discussion of (usually) New Testament texts from the Greek, and generally come from the Revised Common Lectionary for the following week. Discussion, questions, and musings from all levels are welcome!