"You will see" in Spanish is "Veré" (singular and informal) and "Verás" (singular and formal).
"Veré" would be talking to an older person who you want to show respect to. Example: grandparents, teacher, principle, boss, friends, etc.
"Verás" is informal and us usually said to younger people such as younger family memebers or younger people than yourself. Example: Children, toddlers, babies, and possibly parents, etc.
