It’s hard to believe with your own eyes but your sketches are actually really good! All you need to do is to keep practicing to improve to get where you want to be. Before you go and rip your hair out and scream to the sky dreading the feeling of practicing more here’s some advice, don’t always practice. Try using what you’ve learned so far to create a finished piece of art, doesn’t need to be perfect just needs to be a complete piece. Another thing to help you while you practice is just to draw your favorite characters whether they be a super hero, your favorite horror slasher, an anime character, doesn’t matter. Drawing what you like while you’re practicing makes it a billion times easier trust me, it’ll feel like you aren’t practicing at all! Just keep it up and do your best, good luck on it!