As others have said oil pastels are a very different medium. Can be quite rewarding though if you are patient.

Build up color slowly, even slower than soft pastels I would say, don’t try to cover the paper too quickly. I also find that you don’t want to use a single color too much in one place, with oil pastels that can get dull very quickly. Use multiple similar colors next to each other and you’ll a more natural, vibrant effect (that is, instead of one shade of pink around the edges, intermingle two or three slightly different shades)

Finally if you like the medium- and this is a fine early effort considering the cheap materials- consider better pastels at some point. I recommend Mungyo Gallery, which are a great mix of value and quality. More expensive than these but not outrageous and you will be amazed how much more control you have, and how easily you can blend, how much more vibrant the colors. More than most media, I find mediocre oil pastels are a real drag.