hey!! thats great that your usings the tuner! i still havent bought one! haha
well basically ignore the G3 or G4. Yes your doing it correcly tuning it in the scale of G. Im using high g actually but thats still ok. Most people tune there ukes to low g. But i like it High! I only know a couple of songs, But moslty trying to learn Jakes Shimabukuro. Im currently not learning any other songs because i havent got the time to practise, but if you wanted to check out what i play, you can go on youtube. The Link its on my signature!
i dont use a tuner i only use the internet.
i do recommend buying an electric tuner on ebay.
in melbourne there is a store in the city on russell st ooposite greater union movies called "lewis music store"
give that a go and let me know