First, try to orient yourself with your back towards the smoothest, most open area and type “/stuck” in the chat bar. This will attempt to free you.
If it does not work, you can attempt to use one of your free teleport options to liberate yourself.
Your class may have a charge or other movement ability; you can try to use one of them to escape the geometry that has you stuck.
If none of this works, Customer Service is happy to help you through Petition. I understand however, that there are a number of workarounds that may be helpful while waiting for a GM to reach you. For example, logging out for 10-15 minutes can slightly reset your position.
If you have any further questions about the various ways to contact Customer Service, feel free to check out this topic!