What a coincidence! I also have an undergrad degree in Management Information Systems. I actually got another degree in web development with a minor in software development at the same time, so I skipped a step, but I made a similar jump from being a software engineer to being a creative designer.
I was working as a software engineer when I decided to move to a design profession instead. I worked as a Front End Web Dev in the interim.
You will need to start with the basics. Look up W3 schools and start with their HTML, CSS, PHP, and Javascript tutorials. They will take you step by step and offer the basic principals of web development.
Once you have those skills mastered, look into learning Wordpress or other CMS platforms. Wordpress will offer lots of design flexibility and it will be a great sandbox for you to start out your web development career. Wordpress has many tutorials that will walk you through the basics of web hosting and set up.
Familiarize yourself with web design standards and accessibility standards. You want to make sure your web designs follow basic hierarchy rules and provide a good user experience. Accessibility is often overlooked, but extremely important. Your potential clients could fall victim to lawsuits if your web designs don't follow accessibility standards. It will be partially your job to make sure this doesn't happen.
Make yourself a portfolio. Employers will expect you to have a portfolio in most cases. This will help you a lot if you have no professional experience because it offers you a chance for personal learning experience. Make a few demo websites in Wordpress to add to your portfolio.
Include at least one blog, 2 different e-commerce layouts, and an agency style template. You can find some great examples on Themeforest. These do not have to be real companies, of course, just some projects to get you started and set you up for success.
Once you have your portfolio together, start applying for entry level front end development jobs. Remember to never stop learning and improving your craft.