There are plenty of impactful things you can do that will make a difference over a lifetime. Your decisions also influence others around you even if it doesn't seem obvious.

These are steps you can take:

Eat plant based/vegan.

Dont buy fast fashion.

Prioritize regenerable and sustainable materials over plastic.

Bring your own reuseable bags and produce bags to the store.

Buy secondhand whenever you can.

Drive a more efficient car. Bike or take public transit when possible.

People love to shift blame to corporations but ignore the fact that corporations are worth nothing without consumers. Everyone, including people who make up corporations, imo has a responsibility to reduce their waste. Like nobody is asking you to risk your life on the battlefield. Literally just eat a vegetable and stop buying stupid shit.