Freelance Web Developer tools [closed]

Question

I'm thinking of freelancing and building web sites in my free time.

I have experience in C#/ASP.NET, JavaScript/jQuery as well as HTML/CSS and SQL. Thus, I feel like I have sufficient web technologies knowledge to go down this path.

What I'm unsure of is if there are any tools which can be used to simplify the life of a freelance web dev. As an example, I once designed an e-commerce website from scratch as a University project, which took around 3 months of hard work to accomplish. The finished product was not even hosted, and I didn't delve into any security aspects. I never even hosted a website or database before!

What concerns me is that there are millions of sites out there which can for example be used to create an e-commerce site in minutes. Without having to bother with databases, security and other issues. You don't even need to know how to code in server-side technologies to get these sites up and running.

Do professional web developers actually use these tools? If a client had to request an e-commerce site (for example), how would a pro go about developing it? I hear a lot about CMS systems like Joomla and Wordpress, but I think my main problem is that I don't know much about the available tools (other than Visual Studio) and I wouldn't know where to get started.

Can anyone guide me in the right direction?