From the PHB, page 164:
Spells Known and Prepared. You determine what spells you know and can prepare for each class individually, as if you were a single-classed member of that class.
So for the purposes of spells known and prepared, as far as the Druid class is concerned, you are just a level 1 Druid. That being the case, you know 2 Druid cantrips. As a Druid, you know all the spells from the Druid spell list. Finally, as a level 1 Druid, you can prepare a number of spells equal to 1 + your Wisdom modifier every day.
Note that your spell slots are given in the table on page 165 for multiclass spellcasters. As a Druid 1/Wizard 1, you have 3 1st-level spell slots.