There are no 0 level spells, they are moved to 1st level.
Cantrip is a tag on certain spells, allowing it to be cast at reduced effect without losing it from memory.
Spells from Basic:
Bless: As a cantrip can add +1
Burning Hands: 1d6 as a cantrip
Fire Bolt: 1d10 as a cantrip, or 2d10, and 1d10...