Always do step by step exercise. First do mild exercise and then gradually you can increase duration and mode of exercise. Always start with proper warm up then do proper exercise and lastly go for cool down phase. For now to decrease pain u can apply ice pack.

Usually you should start with proper warm up exercises before running and end with cool down exercises. If it is the first day of your running then you may have pain because of something called Delayed onset muscle soreness. Apply ice pack, do stretching under guidance and have adequate water. It takes 2-3 days to get settle down.

Stop running apply ice pack and do stretching exercise

You should do proper warm up and cool down exercises with proper guidance before you start your workout. You can give ice therapy after your workout to reduce muscle soreness.

If you was 1 st day online class of physical activity don't worry take continue but before ran at least do warm up exercise for 10 to 15 min like light all body muscle stretch for eg- back ,leg and upper limb(both shoulders)

Stop immediately 1. Don't do any sort of physical exercises without a physiotherapist or fitness expert knowledge 2. Sometimes it may end up in dangerous situations. 3. First start with full body stretching,  core , free exercises then u can start running after a week time 4. DR.ANDREW JAYA SINGH senior sports physiotherapist head to heel physiotherapy clinic porur Chennai 5.https://youtu.be/AFSMfLCVaGo

Chiropractic adjustment will help. Quadriceps exercise Hams Stretching- lie straight, take the leg up, pull the feet towards yourself, with a elastic tube or normal belt. repeat 10 times, twice a day. Sports Taping- stretch the tape from both ends and apply on the affected area Contrast Fomentation (Hot and Cold). Chiropractic physiotherapy.

It is common to get pains after starting exercises, no need to worry, you can continue the exercises. There will be pains for about 3 - 4 days, then there wont be any discomfort, always remember do not get stressed, take a break if you get tired.

You should ice pack then hot pack. And stretch if you can. The muscle soreness could be there for 4 to 5 days. After 2 or 3 days, you could start some walking.