What does this notification mean above my questions in my Stack Exchange profile?
Have you considered accepting an answer or starting a bounty for this question?
What do I need to do?
Your profile shows that you've asked a bunch of questions but haven't accepted any answers. Instructions for accepting answers can be found in Accepting answers what is it all about?
The system is basically trying to help you out. When you accept answers the people who answered the question get a little bit of reputation (the score by your name). Think of it as a "thank you". Your badge shows "0% accept rate", which means you haven't accepted any answers at all, so it looks like no one has been able to answer any of your questions. From what I can see people with decent accept rates get good answers, as they tend to follow up and accept people's answers as the correct one.
Clicking on your username will take you to your user page, which will show what questions you've asked. If someone's given you an answer that answers your question, give them a +1 vote and check the checkmark!
You can use the search to find out which questions you have not accepted yet by searching for
Ok, so accepting an answer gives the person who answered it some reputation. So what? What's in it for you? A measly 2 reputation points? How about something a little more helpful?
Well, when you accept answers to all your questions, it establishes that answers to your questions are worth more reputation points. So when you ask questions in the future, people will be more willing to spend more effort to bring you better answers to those questions, because they know there are rewards.
So, accepting answers to your questions makes this website more useful to you, by improving the quality of future answers to your questions. It's a positive feedback loop, and it's part of the genius of the whole StackExchange platform.