I'm noticing something here and wanted to bring attention so that you all are aware. It's the balance between progress in "Levels" and progress in your "Certification". Most of us are more focused on the "Levels" instead of the "Certification". I'm striving to balance this now - although I have to say that the "community" work is far more FUN than the "classroom" work - LOL!!!
Getting to "Level 4" (click on Community to post and receive likes and give likes to others) is only important so you can unlock the Modules for "Certification" (click on Classroom at the top menu). Thus, technically you have only need to accomplish up to Level 4 so you can finish all modules in the Certification Coursework.
When you look at your profile by clicking on "LEADERBOARDS" in the top menu there are a few things to discover. Your profile picture has a grey ring around it at the beginning (see my profile pic below). As you complete the classroom modules the grey turns to blue. This is an indication of your progress through the Certification Coursework. As you can see, my pic has a Level 6 indicator and the ring is about 2/3 blue - I just finished Module 2 videos. (To "complete" the modules 100% there is a checkbox above the video box on the Right hand corner - see image below). This profile view also has your Level and below that the points required for your next Level UP (with a question mark). Click on the question mark and it shows the Levels with point requirements as shown below in the pic.