Druids (and clerics) have all spells available to them. Each day, you prepare a small subset of those spells, and these are what you have available to cast. You are limited by the number of spell slots as far as how often you can cast, but so long as you have a spell slot available you can cast one of the spells you have prepared.
So, for your Druid spells, you have everything under 1st and 2nd level on page 208 of the PHB available to you.
You can prepare a number of spells to cast, which is equal to your WIS modifier plus your druid level. For example, if your Wisdom is 16, you have a +3 modifier, add to your level (3), and you have 6 spells you can prepare. You choose these 6 spells from the list on page 208. You can pick any number of spells to prepare from the 1st and 2nd level lists, so you could have three 1st and three 2nd, or one 1st and five 2nd.
At level 3, you have four 1st-level spell slots and two 2nd-level spell slots. These determine how often you can cast those spells you just prepared.
Prepared spells stay with you until you decide you want to prepare a different set, which requires a long rest and meditation of 1 minute per spell level of the spell you want to prepare.
You can cast your prepared spells a number of times equal to your spell slots. So if you wanted to, you could have Cure Wounds prepared and cast it 4 times at 1st-level and 2 times at 2nd-level.
Taking a long rest restores your spell slots.
Last edited March 15, 2016 6:38 pm