There are tips and strategies for managing anxiety offered by various entities. This is one: https://adaa.org/tips
Although I don't meditate very often, I have found that to be helpful. There are many guides you can look up for that. But basically all you do is sit in a comfortable position (not so comfortable you might fall asleep), typically on a cushion on the floor, with eyes closed, and pay attention to your breathing. Try to think of nothing else except focusing on your breathing. You will inevitably have thoughts crop up in your head. When that happens, go back to focusing on your breathing so that it's the only thing on your mind, if possible. Do this for 10 minutes. (Set an alarm if you don't want to find yourself thinking about the time.)