Why don't I see any matching jobs?

You can find jobs in your account under "Find an opportunity". Your search filters are automatically preset according to your preferences–removing those filters allows you to see more projects. If you try that and you still don't see any matching projects, it could be due to a number of reasons.
For example, if your profile and skills are not complete, you won't see any jobs. In addition, the more detail you provide for your listed skills, the higher the probability of finding a project that matches those skills.
Finally, it could just be there are no available projects for your skillset, at this time. Just try again later.