I would totally recommend that you start sketching and posting your sketches here daily for feedback! It's a great way to focus your efforts and keep committed to learning and improving. Getting feedback really makes the difference with how fast you'll improve.
If you want to have a guide to follow, one book that's a set up to teach sketching from the beginning is How to Draw by Scott Robertson. It gives you a bunch of great exercises to train your eye and arm to learn the fundamental muscle control for sketching and it also goes really deep into perspective.
Don't worry about posting something you're not as proud of for a first try! If you keep it up you'll enjoy looking back on where you started. Looking forward to seeing you sketches, good luck!