How do I make varying health values based on what class a player choose?

I'm trying to make a Hero Shooter with each class having a specific weapon, ability, and health value.

The player object has a property maxHitPoints. You can just set this to whatever you want, e.g. player.maxHitPoints = 150

If you want to save their progress you will need to read up on data storage, there are some examples here: Storage