Basically in dnd 5e heroism spell a willing creature which you do touch has been imbued with the bravery. Until the spell would end, the creature is immune for being frightened and also will gain temporary hit points which are equal to your spellcasting ability modifier at each of its starting turn.
But whenever the spell ends then the target would lose any of its remaining temporary hit points from this heroism 5e spell.
At Higher Levels Of D&D 5E Heroism
Whenever you do cast this spell by using the spell slot of 2nd level or more than the 2nd level and then you can easily target an additional creature for each of the slot which is above the 1st level.
Attributes Of Heroism D&D 5E
|Casting Time||1 action|
|Duration||Up to 1 minute|
|Higher Spell Slot Desc||When you cast this spell using a spell slot of 2nd level or higher, you can target one additional creature for each slot level above 1st.|
|Target||A willing creature you touch|