I just realized something about English: the preposition depends on the verb. For verbs of placement, we use “into”: He puts the clothing into the box. For verbs of location, we use “in”: The clothing is in the box.
Also we tend to say “on the beach” if we are nearby: Jorge is on the beach. But we say “at the beach” if we are in a different city: My friends are at the beach.
Hope this helps with your translations. When I teach basic English, the use of “in”, “on”, or “at” is one of the most challenging things for Spanish speakers.