Koine Greek pronunciation

Hello, my goal is to learn Koine Greek so that i can grow in the knowledge of the Lord Jesus Christ.

I would appreciate some help. I want to know where can i find a chart with a historic Biblical Koine Greek prounuciation ? I dont want to learn Erasmian or Modern pronunciation.

And a couple of more questions.

Is the grammar, the meaning of the words and spelling of Koine Greek the same as Modern ?

What are the differences between Koine Greek and modern Greek ?

Here is the best explanation I’ve seen of Koine pronunciation: http://www.biblicallanguagecenter.com/koine-greek-pronunciation/

Koine Greek is in between Classical (Attic) Greek and Modern Greek - but much closer to Attic.

Thanks.