Q.My herbs are leaning
How do I fix this? I am currently growing Tarragon in a pot and it has been increasing in height rather quickly. The problem is, it tends to lean towards one side so it isn’t standing upright at all. I heard that this is due to the fact that herbs tend to lean towards the sun, but it still isn’t straight even though I have been turning its pot regularly. What can I do for it to straighten?

Yes, it likely isn't getting even bright light. This can be correctly generally by turning the pot at least once a week.
You also can prune up the plant to have a more even appearance. Also when you need to repot, you can adjust the placement in the pot.
If the plant is healthy, I would not worry to much about an uneven plant.
https://www.gardeningknowhow.com/edible/herbs/tarragon/growing-french-tarragon.htm
https://www.gardeningknowhow.com/houseplants/hpgen/rotating-houseplants.htm