Why do my calves get stiff while i am running?

Hey whats going on people i have been runing for 2 weeks and now i have started lifting weight also but now my calves get so stiff i cant even run like i used two also my feet hurt is it because i have my shoes tied two tight cause sometimes it help to untie my shoes a little bit i wear new balance shoes what cause my body to do this also my lower back get very stiff two why am i haveing there problems i am 5'10 male 235 in weight i really need to get this weight off can somebody help me out and also what is a good fat burner i can use to help myself out loss this fat a littler quicker