I'm taking a sentence from page 49-138 of Lake and Ura's Learn to Read in Japanese
The first part of the sentence (ブラジルに行く準備ができて) and last part of the sentence (飛行機に乗るだけです) seem pretty straightforward, but I'm not sure where 後は fits in with those. If it's associated with the first part of the sentence, it seems like it could mean
After the plans to go to Brazil are finished, there's nothing to do but get on the plane.
but if it's associated with the second half of the sentence, it might mean something more like:
The plans to go Brazil have been finished; later there's nothing to do but get on a plane.