maybe an injection to calm things down.

If not better after several weeks MRI would likely be ordered to confirm diagnosis and severity.

Partial torn meniscus can sometimes heal ok with conservative treatment but may need surgical intervention if symptoms remain after conservative treatment.

Fully torn meniscus won’t heal on its own and likely would need surgery if painful.

There are two options with meniscus surgery. One would be to repair it. This is more likely for younger patients or active/athletic patients. Or meniscectomy which basically trims all the bits away that are catching and causing problems, potentially all of the meniscus. This is more likely for older or less active patients or depending on the type of injury.

You could go back to running after healing following either procedure. Recovery is longer and more detailed following a repair.

FYI, I’m not a Dr., I just work for one so take that all with a grain of salt. I have no real training in treating anything but I’ve picked up a thing or two along the way. And this is all supposing you even have a meniscus injury. Might be something else entirely.