Great to see you decided to make a sketchbook and wanted to formally welcome you into the Conceptart Community! We are an incredible community and im sure many will help guide your path like they are helping mine! I would like to suggest maybe you do some figure drawing in your next post! Welcome and Keep posting !!!
Good work, I can see the effort you put in.
Keep in mind that everything you draw = practise. Try something more imaginative for a change and don't worry too much about getting things "right". Of course it's important to learn your fundamentals, but you can only learn these by drawing them a million times... why not express yourself and have fun while you're at it? You can -always- use references to back up your work!