Why is my printer telling me there is no ink?

I have an HP Deskjet 1050 printer. I just bought new ink for it. I made sure it was HP Ink. My boyfriend put the ink in and I also made sure I had enough paper. However, there are two little droplet icons flashing on the printer when I try to print something. What is it not restering the new ink and what are somethings I can do. Btw I am not good with these types of things so simple instructions would be good. Please help.