how to find Greek alphabet

If you just need an occasional greek letter, use the Character Viewer (Edit > Emoji & Symbols).

If you need to type greek text, activate the Greek keyboard by using the + and add buttons in system preferences/keyboard/input sources.

macOS Sierra: Use emoji and symbols

macOS Sierra: Use input sources to type in other languages

roobol-hill wrote:

I still would like to know how to put in the accents in a Greek word.

If you are typing modern greek with the greek keyboard, then the accented characters are made by typing the ; key (to the right of the L) and then the base letter. ¨ is made with Shift - ; and then the base letter. ΅ is made with Shift - w.

If you are typing ancient greek, you need to activate the Greek Polytonic keyboard.