We visited Schonbrunn Palace because, of course, when in Vienna, you must see the Schonbrunn. You can get there via metro, and there is a "Schonbrunn" stop to make things easy, It is a bit of a walk from the stop to the palace, but there are signs and lots of people to follow.
We were there in December so could not admire the gardens. Inside, it was confusing, even though we already had a timed entry ticket. Mobs of people everywhere trying to navigate where to go, as signage was not what you would expect. Finally inside, it was just a zoo. So, so crowded that it made the palace hard to enjoy.
If there is such a thing as a "slow time" to visit Schonbrunn, I recommend going then. We went early in the morning, but it was crowded even then. I hope you are able to enjoy your visit.
Did I mention the crowds?More