Jag vill is blunt at a counter. Swedish softens it to jag skulle vilja, which is the conditional of vilja, or to jag vill gärna ha. Skulle du kunna is the equivalent when you are asking someone else to act.
Examples
- Jag skulle vilja ha en biljett tur och retur till Malmö.
- I would like a return ticket to Malmö.
- Jag skulle vilja resa i första klass.
- I would like to travel first class.
- Skulle du kunna säga när tåget går?
- Could you tell me when the train leaves?
The mistake to avoid
Skulle vilja needs both words - skulle on its own means would, not would like.
Where this fits in
Travel & directions, Swedish A2: Get around in a Swedish-speaking city: take transport, ask the way, check into a hotel, and buy a ticket.