Learn Spanish (Latin America): Quisiera una bata limpia para el sauna.

Quisiera is the imperfect subjunctive form of the verb querer. In Spanish, using this form is a standard way to soften a request, turning a direct 'I want' into a much more polite 'I would like'. It is perfect for customer service situations like asking for a robe at a spa.

How is quisiera different from me gustaría if both mean 'I would like'?

While both are polite, quisiera is the standard choice when you are actively requesting a specific thing or a service from someone, like asking for una bata. Me gustaría is often used more for expressing general desires or hypothetical wishes, like saying you would like to visit a country someday.

Why does the sentence say el sauna when the word ends in an A?

Sauna is a borrowed word from Finnish. In Latin America, it is almost exclusively treated as a masculine noun, which is why it takes el. If you ever travel to Spain, you might hear it used as a feminine noun (la sauna), but el sauna is the standard across Latin America.

Why do we use para instead of por for 'for the sauna'?

You use para here because it indicates the purpose or destination of the object. The clean robe is intended specifically to be used in the sauna. If you used por, it would sound like you are trading a robe in exchange for a sauna.