Good morning as I can understand from your question that you only have gap between your front teeth. The most common way of closing the gap is through orthodontic treatment where they put braces on your teeth. If the gap is not big a composite build up maybe done on the teeth to close the gap, also there is option of full and partial veneers to correct the problem.
Next Steps
The cost of all these treatments vary with city and doctor but since all of them come under category of smile correction aesthetic treatment they could be little on expensive side.