To update the content, i.e. the results you get, you need to alter the content that is crawled and update your config. More information on managing this here.
To alter the style, see this doc.
To do more in depth changes, see this doc. If that's not enough, you can always use instantSearch.js instead.
The free DocSearch plan, doesn't include technical web support from the Support team. For further assistance, you can post your question on the Algolia Community Forum or Discord. For front-end issues, you can raise the issue directly on GitHub. In addition, you can review our DocSearch Documentation and FAQ.