You can scroll down a person's profile and if any of it appeals to you, you can tap the heart icon to like it. You can also add a comment to be sent with your like. Sending a like will put you in their Likes You section and they'll be notified. 

If you like anything on another person's profile that is in your Likes You section, it's a match, and you'll both be notified.

Once you're matched, you can start chatting and set up a video date.

You can find your matches/chats by tapping the chat icon at the bottom of the screen. 

Please note: You have 5 days to set up a video date before a match expires.