Honestly, the best thing you can do is get headshots asap. But, if you absolutely don't have the money or don't want to for some strange reason, this is what you should do to get work:
1. Take a picture of yourself and submit it all around to different projects. Remember that there is no way you'll get called in with no photo.
2. Submit to a bunch of free student films. If you act in plays, be sure to record them so that you can use the samples.
3. Follow up with everyone and make sure you get copies of what you acted in.
4. Make a reel from them.
5. Post it online, showing your best acting skills.
6. Start submitting to paid projects and sending your reel. It will take a while without a good headshot but eventually you'll get a paid job.
7. Use that money to get professional headshots.
8. Then start only submitting to paid jobs.
9. Sooner or later you'll be on your way to the top!