Glad to see you start sketching Luna. I don't blame you for being hesitant at first--drawing lunar features is probably the biggest challenge that astrosketching has to offer.
Features near the limb are my favorite targets to draw because of the oblique view. Not sure I agree with Frank on the big crater partially drawn being Endymion. If you were in the Crater Boss area, the big crater would more likely be Mercurius. Check out this image by Stefan Lammel.
Endymion is the very big crater on the left. The pair of craters just below it are Hercules and Atlas. Draw an imaginary line through them to a similiar sized crater--that is Mercurius.
Because so much detail is usually visible, one can spend hours on a lunar sketch. This is ok if you're sketching a feature back away from the terminator, but if you're working on or near the terminator, you have to work fast because the shadows change so swiftly. This is why so many of the best sketchers often use black paper--they don't have to spend any time filling in shadows.
Unlike Frank, Carlos, Rich, Pierre, Mark, Erika, and other talented folks on this forum, drawing huge swaths of lunar real estate is a daunting task for some of us.
My suggestion is to pick a single crater or other feature, perhaps one that stands alone, and focus on it. You'll find targets like this scattered around the Moon. Here's an example.
Good luck with your next sketch.