Hey!
Sorry for late reply, I didn't notice the notification about new comment.
You draw cards either by using other cards or when a turn ends, which happens when you click on a new tile, use campfire, altar.
I think you mixed up two different items:
1. Helping Hand - increases max hand size by 1, but decreases health regeneration by 1.
2. Rebirth Potion - destroys all cards, increases draw by 1, pick a random card from a selection of 5.
If you go with the second option, that usually requires either relying on luck or some planning. With the rebirth potion you will be weak at start, till you rebuild your deck. You can have some loot bags lying around just in case you find a rebirth potion and decide to use it ;) - this item also gets rid of all curses so it is pretty situational.
Play a demo on Steam to see a newer version and make sure you don't skip the tutorial (it is very, very short!).
