Quisiera un vaso de agua. I would like a glass of water.
Quisiera ir a Perú algún día. I would like to go to Peru some day.
¿Quisieras acompañarme? Would you like (want) to go with me?
Note: The conditional, querría, is generally avoided.
Usted debiera dormir más. You ought to sleep more.
Usted debiera llamarla. You ought to call him/her.
El jovén no se comporta como debiera. The young man does not behave the way he ought to.