Hey!
I think getting some work experience would be great. I would also focus on attending law firm events, open days, and career fairs so that you can build your relationship with these firms and find out what it is like to work there. Especially because you have a lot of free time, it would be good to attend as many as you can so that you can distinguish between these firms when it comes to writing your applications. With that being said, you could also think about writing applications and how you would answer "Why commercial law?". If you are not sure that you want to pursue a career in the City, this could be a great time to research working in-house or national law firm. The Commercial Law Academy has a great course with law firm profiles, which I would recommend as well as the one with alternative legal careers.