How can I help my sore thigh recover?

RICE= rest, ice, co- Mpression with a bandage and elevate the side to get rid of the swelling. Nsaid's help to relieve pain & swelling. After 3-5 days using a heating pad, which helps to relieve pain, discomfort. Massage &/or therapy can be helpful as well.
Time and stretching. Muscle soreness is a mild form of muscle injury. Your body needs time to recover and heal, often a few days. More serious injuries can take weeks. A solid diagnosis is important first so see your orthopedist! in some cases, stimulating the muscle with activity is helpful to quicker recovery. Let me know if you have specific questions about this further. Nsaids icing stretching are key.