Most likely this:
plantar fasciitisOr this...
sciaticaBut if you have diabetes, it could also be this...
Peripheral Neuropathy but that is a long shot, especially if you are very young still.
For item #1, it is related to (but not the same as) things like carpel tunnel, and is treated by immobilizing the foot and avoiding putting pressure or at the very least, using a supporting brace on the foot. See if an NSAID causes temporary relief of symptoms, and check for local warmth (does it feel 'warmer' to the touch than the other foot?), puffiness, and possible skin pinkness (due to inflammatory response) in addition to the tenderness.
For item #2, taking pressure off the sciatic nerve by using a shoe insert (which changes your standing posture) will cause profound relief after a few days.
For the latter, there is no long term treatment-- it is nerve damage caused by a disorder. The best that a doctor will do is prescribe a systemic nerve pain drug, like gabapentin, which is then taken daily forever.
I REALLY dont think it is neuropathy, and my money is on plantar fasciitis. You did not give enough diagnostic critera though to rule it out. (child diabetes is sadly a thing, and if present, or some other systemic disorder that can cause neuropathic nerve disorder, then option 3 is a scary reality to consider.)
There are probably other things that it could be, but at least in geriatric patients, these are the big 3 causes of leg and or foot pain. Plantar fasciitis fits your symptoms almost perfectly.