Search is now called Discover. Just click on the magnifying glass icon on the lower navigation bar on the App or Mobile Web, or click in 'Discover' on the website via desktop or tablet on the upper navigation bar.
By default you will be shown a list of people who best match what you are seeking, as per the criteria you entered at sign-up. To change this list, you can click on the magnifying glass icon on the top-right on the App or Mobile Web and adjust your search criteria via 'Refine Search'. You can also sort your list as needed, or do more advanced searches, including searching via username.
On the website, your search options can be adjusted via the column on the left, or via the upper sub-menu.
You can sort your list in either Grid or Card view.