How Can Calves And Shins Pain From Physical Workout Be Dealt With?

Hello, my name is Christina. And i just started working out 2 weeks ago. I started slow doing intervals. Run 1min walk 2mins for 30 mins and i am now up to running 3 mins and walking 1min for 30 mins. However, this past tuesday my shin and calves have been hurting really bad. My shins feel tight and so do my calves. My calves feel very very tight and my shins have pain. I am overweight. I weigh 227 and im 5'2. But i have lost 8lbs. I want to get my life together so i am eating healthy and working out. When i do my exercise im not tired i just cant finish becuz my calves and shins hurt. I dont know what to do becuz i dont want to stop working out. I know that i do not stretch very well but i dont know how to make my shins stop hurting. I also think i need new running shoes becuz i got my from a general store. What should i do?