Not at WordPress.com. The ecommerce code will be stripped out for security reasons. If you yourself design and make a product you can link to an off-WP store like Etsy or Amazon or something to let people buy it. Your blog must not, however, primarily exist as a feeder for your shop or staff may suspend it. As long as you do real blog posts rather than just spamming your stuff it shouldn’t be a problem.
If you want to sell stuff other people make, I’m afraid that’s not allowed here.