Welcome to the forum. Which one of the dudes is you? You'll find a bunch of helpful guys here. I'm somewhat of a simpleton when it comes to diving. My advice to you is to work on relaxing at the surface, it's all in the breath up. Clear your head of all worries, being able to get to the fish, blackout, sharks, whatever.. and relax. Depth will come with time and your desire to reach whatever interests you down there. It's mostly psychological. Although nice carbon fins help
Oh and being weighed correctly so you'll float up from 15ft.