You can add e-commerce to any site.
E-commerce comes in many varieties. Whatever system you pick to use, it is important to pick a secure one for being able to take credit card payments. You do not want to have e-commerce transactions going through your own site. This means that you should use a third-party site that is set up with the right security and gives you the peace of mind of not carrying the liability.
The time it takes to set up e-commerce for a site runs the gamut. A simple system could take just a couple of hours and will have less ongoing costs.
If you need e-commerce, I can help you decide the best one for you, educate you on what you need to know, and do the set up.
To learn more, see my blog post: E-commerce on your site