Why do the French people storm the Bastille if Louis XVI had no plan to harm them?

Because it held all the Gunpowder for the french army In Paris

Because they were hungry and living in miserable conditions while the king was living extravagantly and not helping the common people.

He had no plan to harm them so he did not storm the Bastille. They did have a plan to harm him, so they did.

If I take all your money in taxes what you gonna do?

course I dont plan to harm you- just take all your money

"Not wanting to harm" is not the same thing as "Having the best interests of all of his people at heart".

The court of Louis XVI was seen as very extravagant, and as taking no notice of the plight and poverty of many of the people.

Because Camille des Moulins stood on a table outside the Palais Royale and made a speech encouraging the people (who were angry enough, and had enough to be angry about all ready) to begin the revolution.

https://en.wikipedia.org/wiki/Storming_of_the_Bastille Explains it quite well and is good reading.

because he was living the good life while the common peasant was suffering in poverty.

Anger is not rational.

To free political prisoners as a show of force toward the Monarchy and government.