The Business Analyst role is one of the most diverse jobs one could have. It is really hard to figure out in advance what type of projects, tasks, issues you will face.
So the best thing that you can do is have a solid foundation of transferable skills such as communication, facilitation, problem solving, note taking, etc.
In addition, use this time to make a strategic plan on how you will be continuously improving your skills and value as a business analyst. Since you've don't have prior experience as a BA nor have you had any formal business analysis training I would suggest you take at least on fundamental course in business analysis covering a broad range of topics such as: requirements elicitation/management, business process modeling, data modeling/analysis, solution assessment and validation. Basically, a course which will tell you how much you don't know.
The reality is that no one business analyst is proficient in all aspects of business analysis since there are so many aspects which can very greatly by project type, team, industry, toolset, etc. So try to learn to be a generalizing specialist. That means, build a broad foundation and then pick areas of interest and dive deeper by learning from courses, books, webinars, etc.
Also - consider joining your local IIBA chapter where you can network with other business analysts.
Best of luck in your new position!
- Adrian