I have a view of one dimension and 2 measures. I want to sort my table on the basis of the 1st measure only but currently, it is sorting on 2nd measure.

If the Sorting is not working as expected, then you can try Custom sort. Just click on the dimension which you want to sort and sort by dropdown, select field. Now select the desired field on which you want to sort you're in the data table. This is called custom sorting.