Like any medium, when you start our with oil pastels, it can be intimidating. It's a good idea to read up and research to find the starter toolkit. Here is a collection of tools that might help you get set up real quick.
Surface - Oil Pastel is the most versatile of all art mediums and work with a variety of mediums. Pick one in a size of your choice.
prepare your surface- if you're using an unprepared surface like wood, you must put a few layers of gesso to prepare your surface
Drawing- oil pastels are opaque, so you can choose anything from pencils to pens for laying down the drawing.
24 or 36 Set Oil Pastels - i recommend at least a set of 24 colors to start with. Unless you are a seasoned artists, it would be a while before color mixing is instinctual and having a few extra shades of each color will come in handy.
Smudge tools - tortillons are usually used with pencil or charcoal drawing but are very effective in achieving sharp lines and detail using oil pastels.
With this you should be all set to create your first oil pastel masterpiece!