You only regain half of your hit dice on the long rest (one on level 1). Other than that you are correct on how you can decide/split how to spend them. You only regain half of your hit dice on the long rest (one on level 1).
Do you get more hit dice?
A hit die is the die you roll to determine how much your total hit points increase each time you gain a level. So the size of the die affects how much HP you have, since each level you have a better chance of getting more HP. Classes that are supposed to be tough have a larger hit die, and so should have more HP.
Can you spend hit dice to recover hit points?
Player characters can now “spend” hit dice to recover hit points during a short rest. For example, a level 5 barbarian with d12 hit dice and a Constitution modifier of +3 can roll to recover 1d12+3 hit points, and can do this a number of times equal to their barbarian level.
How many dice can you recover during a long rest?
v.2 of BD&D now includes language that indicates a minimum of 1 HD is recovered during a long rest. The character also regains spent Hit Dice, up to a number of dice equal to half of the character’s total number of them (minimum of one die). (p 67)
What happens to hit dice at the end of a short rest?
Short Rest. A character can spend one or more Hit Dice at the end of a short rest, up to the character’s maximum number of Hit Dice, which is equal to the character’s level. For each Hit Die spent in this way, the player rolls the die and adds the character’s Constitution modifier to it.
Is there a minimum amount of hit dice?
The Dungeon Delver and Durable feats grant a minimum amount of hit dice on a roll; half your Constitution modifier. That can help prevent bad rolls on your hit dice from lowering how much you heal. Dwarves may pick up Dwarven Fortitude to spend Hit Dice during combat, if they use the Dodge action.
