To edit your profile page, tap your picture in the upper left-hand corner. You can set or change a photo from this screen by tapping on the circle with your initials and selecting the photo you'd like.
Tap 'Edit Profile' to change the name displayed, title and company.
You can connect to LinkedIn by clicking on the icon on the bottom of the screen (you'll see this only if this option in the app is enabled by your event organizer). If you connect your LinkedIn account, this will allow other attendees viewing your profile to also tap the icon to see your LinkedIn page.
Tap the checkmark in the top right to save any changes.