You might want to promote your company or sell goods on WordPress.com. Is it allowed to promote a company or sell goods?
If you use a Free site then you would not be able to use a custom domain name, and ads will be displayed on your site.
If you select any paid plans, you would be able to use a custom domain name and remove the ads. You can compare the various plans features on this link.
You can use a Free site to promote your company but cannot sell goods. To sell products, you need to sign up Premium or higher plan.
No, only paid plans (ie: Premium, Busines or eCommerce plans) allow you to sell goods.
Therefore, it's not allowed to sell goods with Blogger or Personal plan.
For your reference, there are no limits on the number of visitors to the site on all of WordPress.com plans. If you want a blog or a simple company site, WordPress.com will be a good option.