Hey good idea. Let's go to the nearest stellar system which is Proxima Centauri. It's only 4.2 light years away. Given that we might be able to reach, say, 1/4 light speed with our technology in the next 20 years, it would take roughly 20 years one-way to get to that star. Give the crew a year to explore the planets around Proxima Centauri, then another 20 years back to Earth.
That's forty plus years round trip...to the nearest star in the galaxy. The next nearest is over ten light years away. So we can chalk up over 80 years round trip for that one.
Are you getting the picture? The Milky Way is a very big place, stretching 100,000 light years in diameter. That's why we have no plans to explore the Milky Way. It's way too big and we're way to slow to do that in the expected life-time of our planet.