Ideas for walk-in closet?

I'm about to move into an apartment with 2 walk-in closets. I would like to use one for a grow room. Any ideas and recommendations as to what to use, and how to do this? I want something that will be easily movable as I am saving to put a trailor on my mom's property and will start growing out of the trailor. I don't want to keep it in my apartment for longer than I have to.

My first one I started I did in a lil closet, got pissed at my ex for burning my plants, so I haven't attempted anything since.

I have to rebuy my supplies which really sucks. I'm having a yard sale to help with the costs.

Jennifer