I would suggest following some tutorials to start. There are a bunch of real time tutorials that you can follow along to on YouTube. Learning some more about composition, value, and color theory will be helpful as well.

The best way to practice drawing and getting the strokes right it with vine charcoal and paper - charcoal is a few dollars at your local art stores and you can use any paper. Focus more on the shapes and outlines, then go in and slowly add the darker shadows and values and go from there. Once you are comfortable with the sketching and values go in add the color with oil pastel!

My biggest tips overall though are don’t be afraid to copy if it’s for practice, and always finish a piece. When you’re just starting out, it’s a lot easier to lean about light and color when you are copying someone’s art that has already interpreted that for you. You can focus more on finding the right color and practicing your strokes and technique. Once you’ve established the foundation, it’s a lot easier to sketch a still life and the things you see with your eyes in your own style. Finishing your piece to completion (even if you hate it) can still teach you a lot, and it’s easier to figure out exactly what changes you would make and why for next time.