Congratulations on completing day 1! This was a big day with lots of new concepts. If you took more than a day to do this that's totally fine. If you've got to this point and are thinking "I have no idea what's going on" it's ok to go back and go through it again before moving on.
It good to test your knowledge just after learning something new, it solidifies the connections in your mind and identifies any areas that you should go back over.
The Pro version of 30 Days of JavaScript comes with a 10 question multiple choice quiz at the end of each day, if you want to take these quizzes (and get a host of other Pro features) then consider:
If you upgraded to pro, sign in here