How long does it take to get to a near native fluency level in German?

If English is your native language, then German is possibly the easiest language to learn. But to be fluent in any language you will have to spend some time "immersed" in the language, which means you will need to spend time around only German speakers, speaking only German, such as spending a month or two in Germany. There are also different dialects of German so you'd have to figure out which you want to learn.