Azaleas do not like soil with lime in it (e.g. chalky soil) or one with a high pH level. If people in nearby gardens are growing them, or rhodedendrons or camellias in the ground then you should be ok, otherwise buy a pH test kit to check the level - if the measure is less than 6 you should be ok to plant it in the ground. Otherwise buy a pot for it and some ericaceous compost and plant it in a pot.