Relevance is the default sort order. Other sort orders include Date: newest first, Date: oldest first, Citations: highest first, and more.
Use the 'Refine Results' feature to refine (filter) your results. The first option is to search within the results. Some of the main filters include:
Web of Science provides multiple options for getting full text:
For every result (unless it's very recently published) a clickable citation count is displayed, telling you how often the result is cited by other publications indexed in Web of Science. Click on such a link and a screen will appear with results (mostly articles) citing the result in question.
If you want to start a new search or add additional criteria to your current search, click the search box near the top of the screen, which gives you options to reset all search fields.