The search results could be improved in two ways. First, the results should be as relevant as possible. Second, the should by default be sorted so that the most useful results are on the first page. These are two separate concerns. Sorting is useless if the results are not relevant.
Some ways that the search results might be made more relevant:
Once we have relevant results, we still want to sort them. Obviously, a relevance score can be used in the sorting, but there are lots of other things that could be included: