What happens next?

How to build a model
Take your model kit out of the box and compare the pieces to the instructions to make sure you have everything needed.
Kits do (infrequently) come from the factory with missing or damaged parts. The time to return it to the store is before you begin assembling it!
Wash the parts.
Using an old toothbrush, some dish detergent and warm water, carefully wash the parts of the model while they are still on the parts trees. Rinse the parts thoroughly and allow to dry completely.