Everytime i stand up i have pain and burning in my left foot that starts at my 3rd toe all the way to my ankle. what can that be?

Nerve related: Sound like a nerve related condition: ie: neuroma, neuritis.

Nerve entrapment: Definitely is an entrapment of the intermediate dorsal cutaneous nerve. Visit your local podiatrist for an evaluation and possible nerve block as described in a previous answer.

Neuroma: It is possible you have a neuroma. Make an appointment with a podiatrist

Morton's neuroma: Morton's neuroma is also a consideration versus other neuropathic conditions. Fracture, osteoarthritis less likely. Pinch between the web space of the toes and see if it happens. No matter what try a wide toe box shoe with a firm sole until you get it examined.