I am doing bicep curls standard nothing special, But I don't feel muscle soreness in middle of biceps, i fell it near lower end of it, near elbow one. is it normal or am I doing curls wrong?
I cant say if you're doing the curls wrong without seeing your form. However if you feel pain, then yes you are doing something wrong and should watch videos on proper form.
On the other hand, If you feel like its only targeting a certain part of your bicep, try to add more variety of workouts, try different types of curls such as hammer, seated, etc and see if that helps.
Also adding compound movements to your workout routine, as suggested above, is always a good idea for muscle growth.