Hi webdesignoob. Welcome to the forums.
is there an easy way to implement a simple eCommerce system without resorting to Word Press or outsourcing to a php developer.
Indeed, yes. You basically have three options:
1) install a shopping cart on your site and deal with all the coding and security (probably the best option but the hardest);
2) use a service like Shopify, which is ready made for ecommerce and the whole site is hosted with Shopify, so that you don't have to worry about security etc. You can style the site as you please, and just pay a monthly fee;
3) a middle option is to have your own site but to included payment buttons that take you to a separate, 3rd party site. The simples version is PayPal, but it's a bit ugly, so there are better options like FoxyCart, where you can style the payment pages just like your site so that the customer doesn't know he/she is on a different site.
is there a way to style Word Press with CSS?
Yes indeed. You can totally customize WP with your own theme, styling etc. It can get a bit messy, though, so beware. You really need to know HTML and CSS well, and preferably a bit of PHP. You can also get ready-made themes instead.